Rigid-rod polymers

ABSTRACT

Rigid-rod and segmented rigid-rod polymers, methods for preparing the polymers and useful articles incorporating the polymers are provided. The polymers incorporate rigid-rod backbones with pendant solubilizing groups attached thereto for rendering the polymers soluble.

RELATED APPLICATIONS

This is a continuation of application Ser. No. 07/847,351, filed Mar. 6,1992, now abandoned, which is a continuation-in-part of U.S. applicationSer. No. 07/397,732, filed Aug. 23 , 1989, now U.S. Pat. No. 5,227,457,which is a continuation-in-part of U.S. application Ser. No. 07/157,451,filed Feb. 17, 1988, now abandoned. Applications Ser. Nos. 07/397,732and 07/157,451 are incorporated herein by this reference.

FIELD OF THE INVENTION

This invention relates to soluble rigid-rod polymers having rigid-rodbackbones and pendant, solubilizing organic groups attached to thebackbone, and to methods for preparing the polymers. This invention alsorelates to copolymers comprising rigid-rod segments, having solubilizingorganic groups attached to the rigid-rod segments. The rigid-rodpolymers can, for example, be used as self-reinforced engineeringplastics, can be used in combination with flexible coiled polymerbinders for the preparation of high tensile strength molecularcomposites and can be used as matrix resins for fiber-containingcomposites.

BACKGROUND OF THE INVENTION

High-performance fiber-polymer composites are rapidly achieving aprominent role in the design and construction of military and commercialaircraft, sports and industrial equipment, and automotive components.Composites fill the need for stiffness, strength, and low weight thatcannot be met by other materials. The most widely utilizedhigh-performance fiber-polymer composites are composed of orientedcarbon (graphite) fibers embedded in a suitable polymer matrix. Tocontribute high strength and stiffness to the composite, the fibers musthave a high aspect ratio (length to width). Fibers may be chopped orcontinuous. The mechanical properties of chopped fiber compositesimprove greatly as the aspect ratio increases from 1 to about 100.Mechanical properties still improve but at a slower rate for furtherincreases in aspect ratio. Therefore, aspect ratios of at least about25, and preferably of at least about 100 are desirable for chopped fibercomposites. Composites prepared with continuous fibers have the higheststiffness and strength. Fabricating fiber-containing composites,however, requires significant manual labor and such composites cannot berecycled. Furthermore, defective and/or damaged composite materialscannot be easily repaired.

Molecular composites are high-performance materials which are much moreeconomical and easier to process than conventional fiber-polymercomposites. In addition, molecular composites can be recycled and arerepairable. Molecular composites are composed of polymeric materialsonly, i.e., they contain no fibers. Such molecular composites can befabricated much more simply than fiber-polymer composites.

Molecular composites are materials composed of a rigid-rod polymerembedded in a flexible polymer matrix. The rigid-rod polymer can bethought of as the microscopic equivalent of the fiber in a fiber-polymercomposite. Molecular composites with the optimum mechanical propertieswill contain a large fraction, at least 30 percent, of rigid-rodpolymers, with the balance being polymeric binder. Molecular compositesmay contain either oriented or unoriented rigid-rod polymers.

A molecular composite requires that the rigid-rod polymer be effectivelyembedded in a flexible, possibly coil-like, matrix resin polymer. Theflexible polymer serves to disperse the rigid-rod polymer, preventingbundling of the rigid-rod molecules. As in conventional fiber/resincomposites, the flexible polymer in a molecular composite helps todistribute stress along the rigid-rod molecules via elastic deformationof the flexible polymer. Thus, the second, or matrix-resin, polymer mustbe sufficiently flexible to effectively surround the rigid-rod moleculeswhile still being able to stretch upon stress. The flexible andrigid-rod polymers can also interact strongly via Van der Waals,hydrogen bonding, or ionic interactions. The advantages of molecularcomposites can only be realized with the use of rigid-rod polymers.

Most of the linear polymers produced commercially today are coil-likepolymers. The chemical structure of the polymer chain allowsconformational and rotational motion along the chain so that the entirechain can flex and adopt coil-like structures. This microscopic propertyrelates directly to the macroscopic properties of flexural strength,flexural moduli, and stiffness. If fewer or less extensiveconformational changes are possible, a stiffer polymer will result.

Two technical difficulties have limited molecular composites tolaboratory curiosities. Firstly, the prior art relating to molecularcomposites calls for merely blending or mixing a rigid-rod polymer witha flexible polymer. It is well known in the art, however, that, ingeneral, polymers of differing types do not mix. That is, homogeneoussingle phase blends cannot be obtained. This rule also applies torigid-rod polymers and, thus, the early molecular composites could bemade with only small weight fractions of a rigid-rod component. In thesesystems, an increase in the fraction of the rigid-rod component led tophase separation, at which point a molecular composite could no longerbe obtained.

The second technical difficulty is that rigid-rod polymers ofsignificant molecular weight are exceedingly difficult to prepare. Thetechnical problem is exemplified by the rigid-rod polymer,polyparaphenylene. During the polymerization of benzene, or othermonomer leading to polyparaphenylene, the growing polymer chain becomesdecreasingly soluble and precipitates from solution causing thepolymerization to cease. This occurs after the chain has grown to alength of only six to ten monomer units. These oligomers, i.e.,rigid-rod polymers, are too short to contribute to the strength of acomposite. A lack of solubility is a general property of rigid-rodpolymers, hence, synthesis of all such rigid-rod polymers is difficult.

The solubility problem may be avoided in the special case in which theproduct polymer contains basic groups which can be protonated in strongacid and the polymerization can be conducted in strong acid. Forexample, rigid-rod polyquinoline can be prepared in the acidic solventsystem dicresylhydrogenphosphate/m-cresol, because the quinoline groupinteracts with the acidic solvent, preventing precipitation. However,the resulting polymers are soluble only in strong acids, making furtherprocessing difficult.

Before molecular composites can become a practical reality, the problemsof (a) blending the rigid-rod and flexible components into a stablehomogeneous phase, and (b) the low solubility of the polymer, must beovercome.

SUMMARY OF THE INVENTION

In one embodiment, rigid-rod polyphenylenes provided in accordance withthe present invention are linear polyphenylenes in which the polymerchain has at least about 95% 1,4 linkages, and incorporates pendantsolubilizing side groups. Rigid-rod polyphenylenes may be homopolymersor copolymers having more than one type of 1,4-phenylene monomer unit.The number average degree of polymerization (DP_(n)) is greater thanabout 25.

As used herein, DP_(n) is defined as follows:

DP_(n) =(number of monomer molecules present initially)/(number ofpolymer chains in the system)

In another embodiment of the present invention, segmented rigid-rodpolyphenylene copolymers are provided. The segmented copolymers of thepresent invention comprise one or more rigid-rod polyphenylene segmentsand one or more non-rigid segments, wherein the rigid-rod polyphenylenesegments have a number average segment length (SL_(n)) of greater thanabout eight.

As used herein, the number average segment length is defined by:

SL_(n) =(number of rigid monomer molecules present initially)/(the totalnumber of rigid segments at the end of the reaction)

and is essentially the average number of monomer units in each rigidsegment. Each polymer chain typically contains many rigid segments.However, some may contain less than others, or only one rigid segment.The number average segment length may be approximated by:

SL_(n) =(number of rigid monomer molecules present initially)/(number ofkinked or flexible monomer molecules present initially+number of polymerchains at the end of the reaction)

The rigid-rod and segmented rigid-rod polymers of the present inventionare unique in that they are soluble in one or more organic solvents. Thepolymer and the monomers demonstrate a significant degree of solubilityin a common solvent system so that the polymer will remain in adissolved state in the polymerization solvent system. The rigid-rod andsegmented rigid-rod polymers of the present invention are made solubleby pendant solubilizing organic groups (side groups or side chains)which are attached to the backbone, that is, to the monomer units. Thependant organic groups impart increased solubility and meltability tothe polymer by disrupting interactions between the rigid chains,providing favorable interactions with organic solvents, increasing theentropy (disorder) of the chains, and causing steric interactions whichtwist the phenylene units out of planarity. Therefore, such polymers canbe considered to be self-reinforced plastics or single-componentmolecular composites. Thus, the rigid-rod and segmented rigid-rodpolymers of the present invention have incorporated rod-like andcoil-like components into a single molecular species. The rigid-rod orsegmented rigid-rod polymer can also be mixed with a coil-like matrixresin to form a blend, wherein the pendant organic groups act ascompatibilizers to inhibit phase separation.

Rigid-rod polymers produced in the past are, in general, highlyinsoluble (except in the special case of polymers with basic groupswhich may be dissolved in strong acid) and are infusible. Theseproperties make them difficult, and often impossible, to prepare andprocess. We have found, surprisingly, that the incorporation ofappropriate pendant organic side groups to the polymer substantiallyimproves solubility and fusibility. Earlier work has suggested that suchpendant side groups do not increase the solubility of rigid-rodpolymers. However, by increasing the size of the side chain, by placingside chains so that steric repulsions prevent adjacent phenylene ringfrom lying in the same plane, by placing side chains in a non-regular(random) stereochemical arrangement, and/or by matching its properties(principally, polarity and dielectric constant) to the polymerizationsolvent, rigid-rod and segmented rigid-rod polymers of substantialmolecular weight can be prepared. For example, when the polymerizationis carried out in a polar solvent, such as dimethylacetamide (DMAC) orN-methylpyrrolidinone (NMP), the solubilizing organic side groups willpreferably be polar and will have high dielectric constants, such asketones, amides, esters and the like.

The rigid-rod backbone/flexible side-chain polymers of the presentinvention can be prepared in common solvents and can be processed withstandard methods to give a stable, single-component, molecular compositeor self reinforced polymer useful for structural and other applicationsrequiring high strength and modulus.

The rigid-rod and segmented rigid-rod polymers of the present inventionwhen used in a blend with a flexible polymer are the primary source oftensile strength and modulus of the resulting molecular composite. Suchmolecular composites may be homogeneous single phase blends, blendshaving microphase structure, or multi-phase blends having macroscopicstructure. Pendant side groups can be chosen to increase compatibilitybetween the rigid-rod or segmented rigid-rod polymer and the flexiblepolymer. The more compatible system will have finer phase structure. Themost compatible will be miscible and homogeneous single phase. Therigid-rod and segmented rigid-rod polymers of the present invention canbe blended with thermoplastics, thermosets, liquid crystalline polymers(LCP's), rubbers, elastomers, or any natural or synthetic polymericmaterial. It is known in the literature that the properties of choppedfiber composites improve as the aspect ratio of the fiber increases from1 to about 100, with less relative additional improvement on furtherincreases of aspect ratio. It is also known in the literature that insimple blends of rigid-rod and flexible polymers, the strength andmoduli of the molecular composite blend is a function of the aspectratio of the rigid-rod component, and that these blends phase separateon heating (W. F. Hwang, D. R. Wiff, C. L. Benner, and T. E. Helminiak,Journal of Macromolecular Science--Physics, B22, pp. 231-257 (1983)).Preferably, when employed as a self-reinforcing plastic, the rigid-rodpolymer of the present invention will have an aspect ratio of at least100, that is, the backbone of the polymer (not including side groups)will have straight segments with an average aspect ratio of at least100. For structural and aerospace uses, for example, aspect ratiosgreater than 100 are desirable. For other less demanding uses, such ascabinets, housings, boat hulls, circuit boards and many others, therigid-rod polymer backbone can have an aspect ratio of 25 or more.Similarly the segmented rigid-rod polymers of the present invention whenemployed in structural applications will have segments with aspectratios greater than about 6, preferably greater than about 8.

The high strength and stiffness of the soluble rigid-rod and segmentedrigid-rod polymers of the present invention are directly related to theaspect ratio of the straight segments comprising the polymer chains. Forthe purposes of the present invention, by aspect ratio of a monomer unitis meant the length to diameter ratio of the smallest diameter cylinderwhich will enclose the monomer unit, including half the length of eachconnecting bond, but not including any solubilizing side group(s), suchthat the connecting bonds are parallel to the axis of the cylinder. Forexample, the aspect ratio of a polyphenylene monomer unit (--C₆ H₄ --)is about 1.

The aspect ratio of a polymer segment is taken to be the length todiameter ratio of the smallest diameter cylinder which will enclose thepolymer segment, including half the length of the terminal connectingbonds, but not including any attached side groups, such that the axis ofthe cylinder is parallel to the connecting bonds in the straightsegment.

For the purposes of the present invention, aspect ratio will only beapplied to rigid-rod polymers, rigid-rod monomer units, or straightsegments of rigid-rod polymers. The aspect ratio of a rigid-rod polymerwill be taken to mean the average aspect ratio of its straight segments.The above definition of aspect ratio is intended to provide a closeanalogy to its common usage with respect to fiber-containing composites.

The polymer backbone of rigid-rod polymers provided in accordance withone embodiment of this invention will be substantially straight, with noflexibility that could result in bends or kinks in the backbone, thatis, they will have a high aspect ratio. Accordingly, the polymers shouldbe made employing processes which are not prone to the formation ofoccasional kinks or other imperfection which may interfere with therigidity of the backbone. Nonetheless, almost all chemical reactionshave side reactions, and, accordingly, some phenylene monomer unitsincorporated in the final polymer will not have 1,4 linkages, butrather, will have 1,2 or 1,3 linkages (non-parallel covalent bonds).Other side reactions are also possible leading to non-phenylenelinkages, for example, ether linkages or phosphorous linkages. However,the rigid-rod polymers provided in accordance with practice of thepresent invention will have at least 95% 1,4 linkage, and preferably, atleast 99% 1,4 linkage. Any 1,2 or 1,3 linkage in the polymer chain willreduce the average length of straight segments. Thus, a polymer chain oflength 1000 monomer units having 99% 1,4 linkage and will contain, onaverage, 11 straight segments with a number average segment length(SL_(n)) equal to approximately 91.

Rigid-rod polymers provided in accordance with this invention which havegreater than 99% parallel covalent bonds, i.e., where greater than 99%of the backbone linkages are 1,4 linkages, will be exceptionally stiffand strong and will be useful where high tensile and flexural strengthsand moduli are required, as in aerospace applications. Rigid-rodpolymers having between about 95% and 99% parallel covalent bonds willbe useful for less stringent applications, such as body panels, moldedparts, electronic substrates, and myriad others. In one embodiment ofthe present invention, non-rigid-rod monomer units may intentionally beintroduced into the polymer, to promote solubility or to modify otherproperties such as T_(g) or elongation to break.

The polymers provided in accordance with practice of the presentinvention can be homopolymers or can be copolymers of two or moredifferent monomers. The polymers of the present invention comprise arigid-rod backbone comprising at least about 25 phenylene units,preferably at least about 100 phenylene units, wherein at least about95%, and preferably 99%, of the monomer units are coupled together via1,4 linkages and the polymer and its monomers are soluble in a commonsolvent system. Solubility is provided by solubilizing groups which areattached to the rigid-rod backbone, that is, to at least some of themonomer units of the backbone. Preferably, a solubilizing group isattached to at least 1 out of 100 monomer units.

For the purposes of the present invention, the term "soluble" will meanthat a solution can be prepared containing greater than 0.5% by weightof the polymer and greater than about 0.5% of the monomer(s) being usedto form the polymer.

By "solubilizing groups" is meant functional groups which, when attachedas side chains to the polymer in question, will render it soluble in anappropriate solvent system. It is understood that various factors mustbe considered in choosing a solubilizing group for a particular polymerand solvent, and that, all else being the same, a larger or highermolecular weight solubilizing group will induce a higher degree ofsolubility. Conversely, for smaller solubilizing groups, matching theproperties of the solvent and solubilizing groups is more critical, andit may be necessary to have, in addition, other favorable interactionsinherent in the structure of the polymer to aid in solubilization.

By the term "rigid-rod monomer unit" it is meant the basic, organic,structural units of the polymer rigid-rod backbone chain in which thecovalent bonds connecting them to adjacent monomer units are parallelregardless of conformational changes within the rigid-rod monomer unit.For the purposes of this invention rigid-rod monomer units will belimited to 1,4-phenylene units, including any attached side chain, i.e.,solubilizing groups.

The term "monomer unit" will always be used in the present invention tomean "rigid-rod monomer unit." In the instances where a flexible ornon-rigid-rod monomer unit is discussed, it will be indicated as a"non-rigid monomer unit." Most non-rigid monomer units cannot attain aconformation in which the bonds to the polymer chain are parallel, forexample, the 1,3-phenylene group or the 4,4'-diphenylether group.However, some non-rigid monomer units will admit a conformation in whichthe bonds to the polymer chain are parallel, such as the phenylene amidetype non-rigid monomer units of a polymer provided by DuPont Companyunder the trademark KEVLAR (polyamide of 1,4-phenylenediamine andterephthalic acid). Polymers comprised of such non-rigid monomer unitsare "pseudo-rigid" due to the possibility of bent or kinkedconformations. Rigid-rod polymers are, in general, stiffer thanpseudo-rigid polymers.

By the term "monomers," for the purposes of the present invention, it ismeant the immediate chemical precursors to the polymer. Because most ofthe polymerization reactions described herein are condensationpolymerizations, a monomer will typically lose one or more functionalgroup(s) with respect to the corresponding monomer unit. For example,the monomer dichlorobenzene (C₆ H₄ Cl₂) polymerizes to a polymer withphenylene (C₆ H₄) monomer units.

The solubility of rigid-rod and segmented rigid-rod polymers provided inaccordance with this invention is achieved by the attachment of pendant,solubilizing organic groups to at least some of the monomer units of thepolymers. One who is skilled in the art will recognize that it isdifficult to determine a priori what combinations of organic substituent(pendant organic group), polymer backbone, polymer configuration,solvent system, and other environmental factors (e.g., temperature,pressure) will lead to solubility due to the many complex interactionsinvolved. Indeed, as is mentioned above, other workers have found thatpendant organic side groups do not provide a substantial increase in thesolubility of rigid-rod oligomers and polymers. We, however, havediscovered general strategies for the rational design of solublerigid-rod and segmented rigid-rod polymer systems. For example, if therigid-rod or segmented rigid-rod polymers are to be synthesized in polarsolvents, the pendant solubilizing organic groups of the polymer and themonomer starting material will be a group that is soluble in polarsolvents. Similarly, if the rigid-rod or segmented rigid-rod polymersare to be synthesized in non-polar solvents, the pendant solubilizingorganic group on the rigid-rod polymer backbone and the monomer startingmaterial will be a group that is soluble in non-polar solvents.

Various factors dependent on the nature of the backbone itself alsoaffect the inherent solubility of the polymer. The orientation of theindividual monomer units, especially with regard to the positioning ofpendant organic substituents, has been shown to have an effect on thesolubility properties of polymers. In particular, 2,2'-disubstitutedbiphenylene units incorporated into aromatic polyesters (H. G. Rogers etal, U.S. Pat. No. 4,433,132; Feb. 21, 1984), rod-like polyamides (H. G.Rogers et al, Macromolecules 1985, 18, 1058) and rigid polyimides (F. W.Harris et al, High Performance Polymers 1989, 1, 3) generally lead toenhanced solubility, presumably not due to the identity of thesubstituents themselves but to sterically enforced non-coplanarity ofthe biphenylene aromatic rings. Extended, planar chains and networks ofconjugated aromatics exhibit good stacking and strong intermolecularinteractions and are generally expected to exhibit high crystallinityand, thus, poor solubility. Random distribution of side chains inhomopolymers and especially copolymers will enhance solubility bylowering the symmetry of the polymer chain, thereby decreasingcrystallinity.

The rigid-rod and segmented rigid-rod polymers (homopolymers andcopolymers) provided in accordance with the present invention will haveat least one monomer unit for each 100 monomer units in the rigid-rodbackbone substituted with a solubilizing organic group, or preferablyone monomer unit for each ten monomer units in the rigid-rod backbonesubstituted with a solubilizing organic group. In general, forrelatively small solubilizing side groups a higher degree ofsubstitution is needed for good solubility. In many instances no morethan 50% of the monomer units should be unsubstituted, for examplecopolymers of 1,4-dichlorobenzene and 2,5-dichlorobenzophenone showappreciable decrease in solubility with 10% unsubstituted units, andonly low MW material can be prepared at greater than about 50%unsubstituted units. The solubilizing organic groups which aresubstituted on, attached to, or pendant to the monomer units are organicmolecules that have solubility in one or more organic solvent system(s).In order that relatively small organic groups, that is, those of amolecular weight of less than about 300, are capable of providingappropriate solubility, other favorable backbone interactions, asdescribed above, may be required. For instance, at least one2,2'-disubstituted biphenylene fragment would be required in thebackbone for each 200 monomer units, and preferably for each 20 monomerunits, and more preferably for each four monomer units in apolyparaphenylene type polymer. In embodiments of the invention, wherethe rigid-rod polymer is a homopolymer, the same organic or pendantgroup(s) occur(s) on each monomer unit. The side chains are chosen toenhance solubility, especially in the polymerization solvent system. Forexample, polar groups, such as N,N-dimethylamido groups, will enhancesolubility in polar solvents.

In one embodiment of the invention, the polymer is a copolymer of two ormore rigid monomer unit types, and the majority of monomer units aresubstituted with solubilizing organic groups. The polymer can be formedfrom two different monomer units or monomers, three different monomerunits or monomers, four different monomer units or monomers, and so on.At least one out of every 100 (1%), preferably 10% and more preferably50% of the monomer units in the rigid-rod backbone has a solubilizingorganic group attached to it.

In another embodiment of the invention, the polymer is a copolymerhaving rigid-rod segments with segment length (SL_(N)) of at least abouteight, and non-rigid segments of any length. In the case where rigid-rodsegments are separated by only a single non-parallel linkage, thenon-parallel linkages represent kinks in an otherwise straight polymermolecule, as for example would be introduced with isolated 4,4'-diphenylether monomer units. In this case the angle between the rigid-rodsegments is fixed. If the non-rigid monomer units have more than onenon-parallel linkage, or if the non-rigid segments have length greaterthan one, the angle between the rigid-rod segments is not fixed, and thecopolymer as a whole has much greater flexibility. In the case of longnon-rigid blocks the copolymer may be considered a single componentmolecular composite, where the rigid blocks reinforce the flexibleblocks.

Where rigid-rod polyphenylene segments are used in a block copolymerwith non-rigid segments, the rigid segments will have a dramatic effecton the physical and mechanical properties of the copolymer forrelatively small aspect ratio of the rigid segments.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will be more fully understood when considered with respect tothe following detailed description, appended claims, and a accompanyingdrawings, wherein:

FIG. 1 is a semi-schematic perspective view of a multi-filament fiberprovided in accordance with practice of the present invention;

FIG. 2 is a semi-schematic perspective view of a roll of free-standingfilm provided in accordance with practice of the present invention;

FIG. 3 is a semi-schematic cross-sectional view of a semi-permeablemembrane provided in accordance with practice of the present invention;

FIG. 4 is a semi-schematic perspective view of a radome provided inaccordance with practice of the present invention mounted on the leadingedge of an aircraft wing;

FIG. 5 is a schematic cross-sectional side view of a four-layer printedwiring board provided in accordance with practice of the presentinvention;

FIG. 6 is a semi-schematic perspective view of a non-woven mat providedin accordance with practice of the present invention;

FIG. 7 is a semi-schematic perspective view of a block of foam providedin accordance with practice of the present invention; and

FIG. 8 is a semi-schematic fragmentary cross-sectional side view of amulti-chip module provided in accordance with practice of the presentinvention.

FIG. 9 is a semi-schematic side view of a fiber containing compositecomprising a polymer provided in accordance with the present invention.

FIG. 9A is an enlarged view of a portion of the edge of thefiber-containing composite of FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

In a first preferred embodiment, the rigid-rod polymers provided inaccordance with practice of the present invention are linearpolyphenylenes which incorporate parallel covalent bonds (1,4 linkages)between monomer units. Such rigid-rod polymers will have at least 95%1,4 linkages, and preferably at least 99% 1,4 linkages, i.e., thepolymers will have high aspect ratios.

The rigid-rod polymers of the present invention have the followinggeneral structure: ##STR1## wherein each R₁, R₂, R₃, and R₄ areindependently chosen solubilizing groups or hydrogen. The structure ismeant to represent polymers having mixtures of monomer units as well asthose having a single type of monomer unit. The structure does not implyany particular orientation, order, stereochemistry, or regiochemistry ofR groups. Thus, the polymer may have head-to-head, head-to-tail, random,block or more complicated order. The particular order will depend on themethod of preparation and the reactivity and type of monomers used.

In another preferred embodiment of the present invention, rigidpolyphenylene segments are separated by flexible monomer units orflexible segments or blocks to give a segmented rigid-rod polymer. Inthis case the flexible segments contribute to solubility andprocessability as well as the solubilizing side groups on the rigidpolyphenylene segments. The rigid backbone of the rigid segments providethe segmented rigid-rod polymer with a high degree of stiffness andstrength, and also modify other properties, such as creep resistance,flammability, coefficient of thermal expansion, and the like, to adegree proportional to the relative amounts of rigid and flexiblesegments. In fact, such physical and mechanical properties can beprecisely adjusted by adjusting the rigid fraction. For example, thecoefficient of thermal expansion of a segmented rigid-rod polymer may beadjusted to match a particular material by controlling the amount ofrigid monomer relative to flexible monomer used in its preparation.

Dihaloaromatic monomers of Structure II may be used in the preparationof segmented rigid-rod polymers. ##STR2## where R₁ -R₈ are independentlychosen from solubilizing side groups and H wherein G is --O--, --S--,--CH₂ --, --CY₂ --, --OCH₂ --, --OAr--, --O(ArO)_(n) --, --(CH₂)_(n) --,--(CY₂)_(n) --, --CO--, --CO₂ --, --CONY--, --O(CH₂ CH₂ O)_(n) --,--(CF₂)_(n) --, --COArCO--, --CO(CH₂)_(n) CO--, --C(CF₃)₂ --,--C(CF₃)(Y)--, --NY--, --P(═O)Y--, X is Cl, or Br, or I and Ar is anaromatic group, heteroaromatic group, or substituted aromatic group, andY is independently selected from the group consisting of H, F, CF₃,alkyl, aryl, heteroaryl, or aralkyl group, and n is 1 or greater.

In order to provide significant improvement in physical and mechanicalproperties over flexible polymers the segmented rigid-rod polymers ofthe present invention should have rigid segments with number averagesegment length (SL_(n)) of at least about 8.

One such exemplary embodiment of the structure of a polymer comprisingrigid-rod polyphenylene segments separated by flexible monomer units(the segmented rigid-rod polymer of the present invention) is asfollows: ##STR3## is a rigid-rod polymer segment, wherein each R₁, R₂,R₃ and R₄ on each monomer unit, independently, is H or a solubilizingside group, and --[A]_(m) -- is a non-rigid segment, for example asderived from non-rigid monomers of Structure II; wherein the rigid-rodpolyphenylene segments have number average segment length SL_(n) of atleast about 8, n is the average number of monomer units in the rigidsegment, m is the average number of monomer units in the flexiblesegment and m is at least 1.

In one exemplary embodiment, the segmented rigid-rod polymer of thepresent invention has structure III wherein --A-- is: ##STR4## whereinB¹ -B⁴ are independently selected from the group consisting of H, C₁ toC₂₂ alkyl, C₆ to C₂₀ Ar, alkaryl, F, CF₃, phenoxy, --COAr, --COalkyl,--CO₂ Ar, --CO₂ alkyl, wherein Ar is aryl or heteroaryl. The flexiblemonomer units in this case may be derived from substituted1,3-dichloroarenes. In another exemplary embodiment --A-- is1,3-phenylene and is derived from 1,3-dichlorobenzene. Other flexiblemonomers and monomer units may be used as are apparent to one skilled inthe art.

The segmented rigid-rod polymers may be used in the same ways as therigid-rod polymers including compression and injection molding,extrusion, to prepare films and fibers, in blends, alloys and mixtures,as additives, as matrix resins, and in other ways apparent to thoseskilled in the art.

Other polymer systems have been described in the past as rigid orrod-like but must not be confused with true rigid-rod polymers providedin accordance with this invention. For instance, long chainpara-oriented aromatic polyamides and polyesters often exhibit ordering,due to various intermolecular forces, into rod-like assemblies andconsequently demonstrate some of the advantages (e.g., high strength)and disadvantages (poor solubility) of true rigid-rod polymers. Suchpolymer systems are actually only "pseudo-rigid" because ester and amidelinkages are not inherently rigid or parallel and only adopt parallelconfigurations under certain conditions. At lower concentrations orhigher temperature they may behave like flexible polymers. It is knownin the art that the theoretical stiffness of aromatic polyamide andpolyester backbones is lower than a polyphenylene backbone. Stifferpolymers will of course have greater reinforcing properties.

The rigid-rod and segmented rigid-rod polymers of the present inventionwill have at least one monomer unit for each 100 monomer units in therigid-rod backbone substituted with a solubilizing organic group.Preferably, the polymer will have at least about one monomer unit in tensubstituted with solubilizing organic groups. More preferably, thepolymer will have more than one monomer unit per 10 monomer unitssubstituted with solubilizing organic groups. The solubilizing organicgroups which are substituted on, attached to, or pendant to, the monomerunits are organic molecules that have solubility in one or more organicsolvent system(s). Solubilizing organic groups which can be usedinclude, but are not limited to, alkyl, aryl, alkaryl, aralkyl, alkyl oraryl amide, alkyl or aryl thioether, alkyl or aryl ketone, alkoxy,aryloxy, benzoyl, phenoxybenzoyl, sulfones, esters, imides, imines,alcohols, amines, and aldehydes. Other organic groups providingsolubility in particular solvents can also be used as solubilizingorganic groups.

In an exemplary embodiment, a polymer of Structure I or III is providedwhere at least one of the R groups is: ##STR5## wherein X is selectedfrom the group consisting of hydrogen, amino, methylamino,dimethylamino, methyl, phenyl, benzyl, benzoyl, hydroxy, methoxy,phenoxy, --SC₆ H₅, and --OCOCH₃.

In another exemplary embodiment, a polymer of Structure I or III isprovided where at least one of the R groups is: ##STR6## and wherein Xis selected from the group consisting of methyl, ethyl, phenyl, benzyl,F, and CF₃, and n is 1, 2, 3, 4, or 5.

In another exemplary embodiment, a polymer of Structure I or III isprovided wherein one of R₁, R₂, R₃ or R₄ is selected from the groupconsisting of --CR₅ R₆ Ar where Ar is aryl, R₅ and R₆ are H, methyl, F,C1 to C20 alkoxy, OH, and R₅ and R₆ taken together as bridging groups--OCH₂ CH₂ O--, --OCH₂ CH(CH₂ OH)O--, --OC₆ H₄ O-- (catechol), --OC₆ H₁₀O-- (1,2-cyclohexanediol), and --OCH₂ CHR₇ O-- where R₇ is alkyl, oraryl.

In yet another exemplary embodiment, a polymer of Structure I or III isprovided wherein R₁ is --(CO)X where X is selected from the groupconsisting of 2-pyridyl, 3-pyridyl, 4-pyridyl, --CH₂ C₆ H₅, --CH₂ CH₂ C₆H₅, 1-naphthyl and 2-naphthyl or other aromatic, fused ring aromatic orheteroaromatic group.

In an additional exemplary embodiment, a polymer of Structure I or IIIis provided wherein at least one of the R groups is --SO₂ X and whereinX is selected from the group consisting of phenyl, tolyl, 1-naphthyl,2-naphthyl, methoxyphenyl, and phenoxyphenyl or other aromatic orsubstituted aromatic groups.

In a further exemplary embodiment, a polymer of Structure I or III isprovided wherein at least one of the R groups is --NR₅ R₆ and wherein R₅and R₆ may be the same or different and are independently chosen fromthe group consisting of alkyl, aryl, alkaryl, hydrogen, methyl, ethyl,phenyl, --COCH₃ and R₅ and R₆ taken together as bridging groups --CH₂CH₂ OCH₂ CH₂ --, --CH₂ CH₂ CH₂ CH₂ CH₂ --, and --CH₂ CH₂ CH₂ CH₂ -- andthe like.

In another exemplary embodiment, a polymer of Structure I or III isprovided wherein at least one of the R groups is --N═CR₅ R₆ and R₅ andR₆ may be the same or different and are independently selected from thegroup consisting of alkyl, aryl, alkaryl, --H, --CH₃, --CH₂ CH₃, phenyl,tolyl, methoxyphenyl, benzyl, aryl, C1 to C22 alkyl, and R₅ and R₆ takentogether as bridging groups --CH₂ CH₂ OCH₂ CH₂ --, --CH₂ CH₂ CH₂ CH₂ CH₂--, and --CH₂ CH₂ CH₂ CH₂ -- and the like.

The rigid-rod and segmented rigid-rod polymers of the present inventionare made in accordance with well-known chemical polymerization andaddition reactions or by novel processes described herein. Suchprocesses for preparation of the rigid-rod and segmented rigid-rodpolymers of the present invention employ chemical polymerizationaddition reactions in solvent systems in which the rigid-rod andsegmented rigid-rod polymers and the monomer starting materials are bothsoluble. Of course, the monomer and polymer will not demonstratecomplete solubility under all conditions. The polymer will likelydemonstrate solubility only up to a certain weight fraction, dependingon the exact solvent-polymer pair and other factors, such astemperature. Obviously, it is not necessary for the monomer to becompletely soluble in a solvent for a chemical reaction to proceed. Asis well known in the art, compounds demonstrating limited solubility ina chemical mixture will completely react to give product due to theequilibrium between dissolved and undissolved monomer, that is,undissolved monomer will slowly undergo dissolution as that fraction ofdissolved monomer is continuously exhausted in the reaction. As isdiscussed above, the monomer and polymer are considered "soluble" in aparticular solvent system when a solution can be prepared which containsat least about 0.5% by weight monomer and at least about 0.5% by weightpolymer.

In order to assure solubility of the monomer and polymer in the solvent,the properties of the appended organic groups must be matched to thoseof the desired solvent. Thus, if the rigid-rod and segmented rigid-rodpolymers are to be synthesized in polar solvents, the pendantsolubilizing organic groups of the polymer and the monomer startingmaterial will be groups that are soluble in polar solvents. Similarly,if the rigid-rod and segmented rigid-rod polymers are to be synthesizedin non-polar solvents, the pendant solubilizing organic group on therigid-rod and segmented rigid-rod polymer and the monomer startingmaterial will be a group that is soluble in non-polar solvents. We havefound that it is very important to match the dielectric constant anddipole moment of the solubilizing organic groups to that of the solventto achieve solubilization. For instance, to achieve solubility in polaraprotic solvents such as NMP, the solubilizing organic groups shouldhave dielectric constants greater than about 5 and dipole momentsgreater than about 1.5.

In general, relatively long organic side chains, e.g. those with amolecular weight of greater than about 300, are preferred to enhancesolubility of the rigid-rod polymers of the present invention.Surprisingly, however, we have found that rigid-rod polyphenylene typepolymers, that is, rigid-rod polymers comprised of linearpolyparaphenylene type monomer units having Structure I can besolubilized with relatively short organic groups appended, e.g., organicgroups with molecular weights from about 15 to about 300. Solubility istypically achieved by a combination of favorable interactions actingtogether. For instance, solubility can be achieved in rigid-rodpolyparaphenylenes substituted with the very small (i.e., low molecularweight) but very polar side chains hydroxy (--OH) and amino (--NH₂).

Planar aromatics tend to stack well, causing them to be very crystallineand, thus, have low solubility. This tendency to stack can be reduced byforcing adjacent aromatic rings, e.g., monomer units, to twist away fromplanarity. This can be effected by the addition of substituents next tothe covalent bonds linking the monomer units, leading to significantnumbers of disubstituted 2,2'-biaryl type linkages. Such units have beenshown to increase solubility when incorporated into other types ofpolymer systems. Therefore, to achieve maximum solubility of short chainappended polyparaphenylenes, either the nature of the monomer units orof the polymerization should be such that significant numbers ofdisubstituted 2,2'-biphenyl linkages are introduced into the polymer.For example, if every monomer unit has a single non-hydrogen side group(R₁ ≠H, R₂ =R₃ =R₄ =H), then a regular head-to-tail catenation will leadto no 2,2'-disubstituted linkages, however, a regular head-to-headcatenation will lead to 50% of the linkages having 2,2'-disubstitutionand 50% 2,2'-unsubstituted. A perfectly random catenation will give 25%2,2'-unsubstituted, 50% 2,2'-monosubstituted and 25% 2,2'-disubstitutedlinkages.

We have found, in particular, that rigid-rod polyphenylenes havingbenzoyl or substituted benzoyl solubilizing side groups are soluble inamide solvents, for example N-methylpyrrolidinone (NMP), and high MWrigid-rod polyphenylenes can be prepared in amide solvents.Poly-1,4-(benzoylphenylene), 1, may be prepared from2,5-dichlorobenzophenone by reductive coupling with a nickel catalyst.The resulting polymer dopes have very high viscosities and may bepurified by precipitation into ethanol or other non-solvents. The driedpolymer is soluble in NMP, dimethylacetamide, phenylether, m-cresol,sulfuric acid, anisole, 5% NMP in chloroform, chlorobenzene, and similarsolvents. ##STR7##

The molecular weight of polymer 1 will depend on the exact conditions ofpolymerization, including monomer to catalyst ratio, purity of thereactants and solvent, dryness of solvent, oxygen concentration, and thelike. The method by which the zinc is activated greatly influences themolecular weight. It appears that the highest MW is obtained when thezinc is most active, that is when the reaction time is shortest. It isimportant that the zinc be free flowing powder which does not containclumps which may form in the drying steps. The method of zinc activationgiven in the examples below is effective and convenient, however, othermethods of activation are suitable including sonication, distillation,and treatment with other acids followed by rinsing and drying. It isalso important that the zinc be well mixed during, and especially at thebeginning of, the reaction.

Molecular weight may be measured by many methods, most of which giveonly a relative molecular weight. Two of the most widely used methodsare viscosity and gel permeation chromatography (GPC). The intrinsicviscosity, [η], may be related to the molecular weight by theMark-Houwink Equation:

    [η]=k·MW.sup.α

For flexible polymers α is typically about 0.6, however, for rigidpolymers α is usually greater than 1 and may be as high as 2. In orderto determine absolute molecular weight, k and α must be obtained fromother methods, or estimated using standards having structure similar tothe polymer under study. Since there are no known rigid-rod polymerssoluble in organic solvents there are no good standards for thepolyphenylenes described here. We can make a crude estimate based on theexpected relationship between viscosity and molecular weight forrigid-rods as has been applied to polyparabenzobisthiazole andpolyparabenzobisoxazole {J. F. Wolfe "Polybenzothiazoles and Oxazoles."in Encyclopedia of Polymer Science and Engineering; John Wiley & Sons,Inc., New York, 1988; Vol. 11, pp. 601-635.}:

    [η]=4.86×10.sup.20 (d.sub.h.sup.0.2 /M.sub.l)(M.sub.η /M.sub.l).sup.1.8

where [η] is in dL/g, d_(h) is the hydrodynamic diameter of a chainelement in cm, and M.sub.ι is the mass-per-unit length in g/cm. If d_(h)is taken to be 10⁻⁷ cm (1 nm), the M.sub.ι of trans-PBT is 2.15×10⁹cm⁻¹, the M.sub.ι of cis-PBO is 1.83×10⁹ cm⁻¹, M.sub.η =M_(w) (M_(z)/M_(w))^(4/9), and M_(z) /M_(w) =1.3 then the, weight-average molecularweight can be determined from the simple measurement of [η].

For polymer 1 we estimate d_(h) ≈1.5×10⁻⁷ cm; M_(l) =4.19×10⁹ cm⁻¹=MW/l=180/4.3Å; and [η]=2.4×10⁻⁸ ·MW¹.8. Thus the polymer of Example 1below has [η]=7.2 dL/g and an estimated viscosity average MW of 51,000.

Intrinsic viscosity is useful as a relative measure of molecular weighteven without Mark-Houwink constants. For comparison the highest reportedviscosity for a polyphenylene is 2.05 dL/g {M. Rehahn, A.-D. Schluter,G. Wegner Makromol. Chem. 1990, 191, 1991-2003}.

Similarly, molecular weights as determined by GPC require a calibrationstandard, and no rigid-rod standards are available. The GPC data givenin the examples below are reported using a polystyrene standard and aretherefore expected to be much higher than the actual weight averagemolecular weights.

The soluble rigid-rod polymers of the present invention can be made byany method which is highly selective for 1,4-phenylene regiochemistry.Non-limiting examples of such reactions are: nickel catalyzed couplingof 4-chloroaryl Grignard reagents, nickel or palladium catalyzedcoupling of 1,4-arylhalides, palladium catalyzed coupling of4-chlorophenylboronic acids, Diels-Alder coupling of monosubstituted2-pyrones (J. N. Braham, T. Hodgins, T. Katto, R. T. Kohl, and J. K.Stille, Macromolecules, 11, 343-346, 1978.), anodic oxidation of1,4-dialkoxybenzene, and addition polymerization of cyclohexadienediolderivatives. The polymer will be at least 25 monomer units in length,preferably at least 100 monomer units in length, and, most preferably,longer than 100 monomer units. The polymer can be a homopolymer of asingle monomer or a copolymer of two or more different monomers ormonomer units. The segmented rigid-rod polymers of the present inventioncan be made using the same methods as for the rigid-rod polymers, exceptthat a non-rigid-rod monomer is added to the rigid-rod monomers beforeor during polymerization.

Processes for preparing unsubstituted or alkyl substitutedpolyphenylenes from aryl Grignard reagents are described in T. Yamamotoet al, Bull. Chem. Soc. Jpn., 1978, 51, 2091 and M. Rehahn et al,Polymer, 1989, 30, 1054. Paraphenylene polymers (made up of monomerunits of Structure I) can be prepared by the coupling of Grignardreagents of paradihalobenzenes catalyzed by transition metal complexes.Thus, a mixture of 4-bromophenylmagnesium bromide (1 mole) and4-bromo-3-alkylphenylmagnesium bromide (1 mole), the alkyl group havingan average chain length of about 24 carbon atoms, will react in an ethersolvent in the presence of a transition metal complex to yield apolyparaphenylene rigid-rod polymer having about one out of two monomerunits substituted with a long chain alkyl group. The transitionmetal-catalyzed coupling reaction proceeds selectively andquantitatively under mild conditions. In another variant of thereaction, 1,4-dibromobenzene (0.5 mole) and a 1,4-dibromobenzenesubstituted with a long-chain alkoxy group (1 mole) can be coupled inthe presence of magnesium metal and a transition metal catalyst in aninert solvent, such as ether, to produce a polyparaphenylene rigid-rodpolymer having on the average about two monomer units out of threemonomer units substituted with a long-chain alkoxy group. A variety ofdihalogenated benzenes (monomers of Formula IA), biphenyls (monomers ofFormula IB), terphenyls (monomers of Formula IC), can be polymerizedusing these methods (R₁ -R₁₂ of monomers IA, IB and IC are independentlychosen from solubilizing groups and H). Dibromo-substituted compounds(X=Br) are the compounds of choice for the reaction; however, in manyinstances, the dichloro compound (X=Cl) can also be used, if thereaction can be initiated. We have found that the NiCl₂(2,2'-bipyridine) transition metal catalyst works satisfactorily forthis reaction. ##STR8##

When the rigid-rod or segmented rigid-rod polymers are prepared underGrignard conditions, the following types of organic groups may reactwith the Grignard reagents, causing undesirable side reactions: alkylhalides, amides, esters, ketones, and the like. Thus, such groups shouldbe avoided as solubilizing side groups when the polymers of the presentinvention are prepared using Grignard conditions.

Coupling of the paradihaloarene monomers is preferably carried out withnickel or palladium catalysts with zinc as the reducing agent. We havediscovered that such polymerizations give soluble rigid-rodpolyparaphenylene polymers with high molecular weights in virtuallyquantitative yields. This approach has distinct advantages, since awider variety of solvents can be employed, such as N,N-dimethylformamide(DMF), N-methylpyrrolidinone (NMP), hexamethylphosphoric triamide(HMPA), benzene, tetrahydrofuran (THF), and dimethoxyethane (DME). Thiscoupling reaction can also be used with monomers having speciallyreactive groups, such as nitrile and carbonyl groups. In addition, zincis less expensive and easier to handle than magnesium. Similar reactionsto prepare biphenyl derivatives and non-rigid polymer systems have beendemonstrated by Colon (I. Colon and D. Kelsey, J. Org. Chem., 1986, 51,2627; I. Colon and C. N. Merriam, U.S. Pat. No. 4,486,576, Dec. 4,1984). Unfortunately, this technique was demonstrated to beunsatisfactory to produce high molecular weight polymers fromsubstituted dihalobenzene type monomers due to deactivation of thenickel catalyst by the substituents.

It was, therefore, unexpected when we discovered that certain mixturesof anhydrous nickel compounds, triarylphosphine ligands, inorganic saltpromoters, and zinc metal were efficient for the preparation of highmolecular weight polyparaphenylenes from the reductive coupling ofparadihalobenzene monomer units substituted with solubilizing organicgroups in anhydrous polar aprotic solvents. It is highly recommended toutilize highly purified (preferably greater than about 99% pure)paradihalobenzene monomer from which any water or other aproticimpurities have been removed. For instance, a mixture of one equivalentof anhydrous nickel chloride, three equivalents of sodium iodide, sevenequivalents of triphenylphosphine, and 50 equivalents of zinc metal iseffective in the polymerization of about 30 equivalents of substitutedparadichlorobenzene monomer. The polymerization reaction is preferablycarried out at about 50° C. but is effective from about 25° C. to about100° C. The ratio of equivalents of monomer to equivalents of nickelcatalyst can vary over the range from about 10 to about 5000, and theratio of equivalents of zinc to equivalents of monomer is at least 1.0.The ratio of equivalents of phosphine ligands to equivalents of nickelcatalyst varies from about 3.0 to about 10 or more. The concentration ofphosphine ligands should be about 2.5M or more to prevent the formationof highly unsaturated nickel zero complexes which lead to undesired sidereactions. Use of inorganic salt promoters is optional. When used, theinorganic salt promoter should be at a concentration of about 0.05M to1M, preferably about 0.1M. Non-limiting examples of inorganic saltpromoters are alkali iodides, alkali bromides, zinc halides and thelike. These promoters reduce or eliminate the induction period which istypical of nickel catalyzed couplings of aryl halides. When rigid-rod orsegmented rigid-rod polymers are prepared by nickel catalyzed coupling,the following types of side groups may interfere with the reaction andshould be avoided: halides, acids, alcohols, primary and secondaryamines, nitro groups, and any protic groups. If side groups of thesetypes are desired they should be introduced in protected form.

When using the nickel-triarylphosphine catalyst described above, onemust be careful to select sufficiently reactive monomers in order toobtain high molecular weight polyparaphenylenes. If the reactivity istoo low, we believe that side reactions are more likely to occur, whichcan limit molecular weight and/or deactivate the catalyst. Also, the twohalide groups of the paradihaloarene monomers may have differentreactivities, depending on the identity and location of the substituentgroups. Therefore, the orientation (e.g. head-to-head, head-to-tail, andtail-to-tail) of the monomer groups along the polymer backbone will belargely determined by the relative reactivities of the halo groups ofthe monomer. Relative reactivities are also important to consider whencopolymers are being prepared. For instance, it is desirable to choosecomonomers of similar reactivities when a completely random distributionof the different monomer groups is desired in the copolymer. Conversely,it may be desirable to choose monomers with significantly differentreactivities in order to obtain block-type copolymers, althoughmolecular weight may be limited if the reactivity of any of the monomersis too low.

In general, it is desirable to have some knowledge of the reactivity ofmonomers or comonomers in order to make some predictions about thequality, structure, or properties of the resulting polymers orcopolymers. For instance, we have utilized a simple semi-quantitativeprocedure (see Example 29) for determining the relative couplingreactivities of various monohaloarene model compounds usingnickel-triarylphosphine catalysts. The results of such experiments canthen be used to estimate the relative reactivities of correspondingparadihaloarene monomers or comonomers. In general, we have found thatto obtain the highest molecular weights, monomers must be chosen suchthat high conversions are achieved within about 4-6 hours when carriedout under the preferred reaction conditions described above.

For instance, if it is desired to prepare the correspondingpolyparaphenylene from the reductive coupling of2,5-dichlorobenzoylmorpholine, one would consider the relativereactivities of 3-chlorobenzoylmorpholine (fast) and of2-chlorobenzoylmorpholine (slow) and would expect a head-to-head andtail-to-tail orientation and that molecular weight might be somewhatlimited. Similarly, if one wanted to prepare a copolymer comprisingparadichlorobenzene and 2,5-dichlorobenzophenone comonomers, then therelative reactivities of chlorobenzene, 2-chlorobenzophenone, and3-chlorobenzophenone should be considered (e.g. from Example 29, we seethat the reactivities are similar, and fast, so a random copolymer withhigh molecular weight would be expected).

Aryl group coupling to afford polyphenylenes has also been effected bythe palladium catalyzed condensation of haloaryl boronic acids asreported by Y. H. Kim et al, Polymer Preprints, 1988, 29, 310 and M.Rehahn et al, Polymer, 1989, 30, 1060. The para-haloaryl boronic acidmonomers required for formation of polyparaphenylenes can be prepared bythe monolithiation of the paradihalobenzene with butyl lithium at lowtemperature and subsequent trimethylborate quench and aqueous acidworkup. These polymerizations are carried out in aromatic and etherealsolvents in the presence of a base such as sodium carbonate. Therefore,this type of reaction is suitable for producing polyparaphenylenessubstituted with organic groups such as alkyl, aryl, aralkyl, alkaryl,polyfluoroalkyl, alkoxy, polyfluoroalkoxy, and the like.

The choice of solvents for the various polymerization or condensationreactions will be somewhat dependent on the reaction type and the typeof solubilizing organic groups appended to the monomers. For thecondensation of aryl monomers employing Grignard reagents withtransition metal catalysts, the solvents of choice are ethers, and thebest solubilizing side chains are ethers, such as phenoxyphenyl, andlong-chain alkyls. Anodic polymerization is done in acetonitrile-typesolvents, and ethers and aromatic side chains, such as phenylether, andbenzyl would be the favored side chains.

The monomer units are known or can be prepared by conventional chemicalreactions from known starting materials. For example, the1,4-dichlorobenzophenone derivatives can be prepared from2,5-dichlorobenzoic acid via 2,5-dichlorobenzoyl chloride followed byFriedel Crafts condensation with an aromatic compound, for examplebenzene, toluene, diphenylether and the like. The paradihalobenzenemonomers substituted at the 2 position with an alkoxy group can beprepared from the corresponding 2,5-dihalophenol by allowing the phenolin the presence of sodium hydroxide and benzyltriethylammonium chlorideto react with the corresponding 1-haloalkyl, such as benzyl bromide.Substituted dichlorobenzenes may also be prepared from the inexpensive2,5-dichloroaniline by diazotization of the amine groups to yieldcorresponding p-dichlorobenzenediazonium salt. The diazonium salt istreated with nucleophiles in the presence of copper salts to form thedesired product.

In addition to being soluble in organic solvents, surprisingly, thepolymers of the present invention may be thermally processed, forexample, by compression molding or by injection molding. For example,injection molded specimens of poly-1,4-(4'-phenoxybenzoylphenylene),have flexural moduli greater than 1 million pounds per square inch(MSI). ##STR9##

Some of the polymers of the present invention will melt to form freeflowing liquids. Poly-1,4-(methoxyethoxyethoxyethoxycarbonylphenylene),3, is a freely flowing liquid at about 250° C. if protected from air. Itwas totally unexpected that high MW rigid-rod polyphenylenes having sidegroups with molecular weights less than 300 could be compression molded.It was even more surprising that such polymers would melt withoutdecomposing. ##STR10##

In addition to solubility, the side groups impart fusibility. That isthe side groups lower the T_(g) and melt viscosity to ranges suitablefor thermoprocessing. Polyparaphenylene devoid of side groups isessentially infusible. It can be sintered at high temperature andpressure but it cannot be injection or compression molded orthermoformed by conventional techniques. Likewise other known rigid-rodpolymers such as poly(benzobisthiazole) and rigid-rod polyquinolines arenot thermoformable. The polymers of the present invention arethermoformable. Rigid-rod polyphenylenes having long, very flexible sidegroups will melt. For example, the triethylene glycol side groups of 3imparts a low T_(g) and T_(m). Even short side groups impart fusibility.Polymer 1 has side groups with molecular weight 105 and no exceptionalflexibility. It was unexpected that polymers 1 and 2 could becompression molded. Surprisingly, even relatively high molecular weight1 ([η]>6, MW_(w) >500,000 by GPC vs polystyrene standard) can becompression molded to translucent to transparent panels.

The polymers of the present invention have very high tensile moduli.Isotropic cast films and compression molded coupons have given moduli inthe range of 1 million pounds per square inch (MPSI) to 3 MPSI. For thesame polymer the modulus increases as the molecular weight increases.The high modulus is a clear indication of the rigid-rod nature of thesepolymers. Tensile moduli for polyphenylenes have not been reported,presumably because known polyphenylenes have molecular weights too smallto give film flexible enough to be tested.

It is well known that rigid-rod polymers form liquid crystallinesolutions if their aspect ratio and hence molecular weight increasebeyond a critical value. Many pseudo-rigid-rod polymers are known toform liquid crystalline phases as they melt. It was therefore unexpectedto find that the rigid-rod polymers 1, 2 and 3 neither form liquidcrystalline solutions nor thermotropic liquid crystalline phases, evenat intrinsic viscosity of over 7 and GPC molecular weights over 500,000.This is an advantage in molding operations where liquid crystallinitycan lead to poor weld lines, poor transverse mechanical properties, poorcompressive strength, and a fibrillar morphology. Polymers 1 and 2, incontrast give nearly isotropic molded panels, show no evidence ofcrystallinity, and do not have a fibrillar structure. The lowcrystallinity of the polymers of the present invention is advantageousin many applications including molding, matrix resins, optical polymers,and blending.

Because the polymers of the present invention are soluble and will meltthey can be processed using a wide variety of techniques. Polymersolutions may be spun into fibers by wet spinning, wherein the polymersolution is forced through an orifice directly into a non-solvent. Thepolymer forms a continuous fiber as it precipitates and may be washeddried and further processed in one continuous operation. Spinneretshaving multiple orifices may be used to form poly-filament yarn. Theorifices may have shapes other than round. The polymers of the presentinvention may also be dry jet wet spun, wherein an air gap is maintainedbetween the spinneret and the non-solvent.

Fibers may also be spun from a gel state. Gels have significantlydifferent visco-elastic properties than liquids, and spinning fiber orcasting film from a gel will often give products with dramaticallydifferent physical properties than those processed from simplesolutions. Fibers spun from gels will can have a high degree ofmolecular orientation resulting in stronger, stiffer fibers.

Fibers may also be spun directly from the melt. This method isenvironmentally the cleanest since it does not require any solvents. Thepolymer is heated and forced through an orifice. Orientation may occurat the orifice as a result of expansive flow. Orientation may also beinduced by controlling the tension on the fiber to cause stretching.Multifilament yarn may also be spun from the melt.

Fibers spun by any method may be further treated to influence physicaland chemical properties. Further stretching, heating, twisting, etc. maybe used to improve mechanical properties. Chemical treatments such assurface oxidation, reduction, sizing, coating, etching, etc. may be usedto alter the chemical properties such as interaction with adhesives,matrix resins, dyes, and the like, and may also alter physicalproperties, such as appearance, tensile strength, flexural strength,resistance to light, heat and moisture, and the like.

Referring to FIG. 1, there is shown a semi-schematic view of amulti-filament fiber 10 comprising a plurality of mono-filaments 12,comprising a rigid-rod or segmented rigid-rod polymer provided inaccordance with practice of the present invention.

The polymers of the present invention may also be fabricated into film.As with fibers many different methods may be used to form films. Sincethe rigid-rod and segmented rigid-rod polymers of this invention areboth soluble and meltable, all of the conventional film formingtechniques are applicable. Films may be cast from solution onto asubstrate and the solvent removed either by emersion into a non solventor by oven drying, under a vacuum or inert atmosphere if necessary.Either continuous or batch processes may be used. Films may also beextruded from the melt through a slit. Films may also be formed by blowextrusion. Films may also be further processed by stretching and/orannealing. Special films such as bilayers, laminates, porous films,textured films and the like may be produced by techniques known in theart.

Films, like fibers, may be oriented by stretching. Stretching along onedimension will result in uniaxial orientation. Stretching in twodimensions will give biaxial orientation. Stretching may be aided byheating near the glass transition temperature. Stretching may also beaided by plasticizers. More complex processes such as applyingalternating cycles of stretching and annealing may also be used with thepolymers of the present invention.

Referring to FIG. 2, there is shown a roll 20 of free-standing film 22,formed from a rigid-rod or segmented rigid-rod polymer, prepared inaccordance with practice of the present invention.

The polymers of the present invention may also be fabricated intomembranes useful for separations of mixed gases, liquids and solids.Membranes may be produced by the usual methods, for example asymmetricmembranes by solvent casting. Filters may be prepared by weaving fibersprepared as described above, or forming non-woven mats from choppedfibers or fibrous material produced by precipitation of polymer solutionwith a non-solvent.

Referring to FIG. 3, there is shown a cross-sectional side view of asemi-permeable membrane 30 comprised of a rigid-rod or segmentedrigid-rod polymer provided in accordance with practice of the presentinvention. As a result of the casting technique, the upper surface 32has very small pores and is denser than the lower surface 34, which hascourser pores. The asymmetric structure of the membrane provides forhigher selectivity and faster flow rates.

Coatings may also be formed by any of the established techniques,including but not limited to: coating from solution, spray coating ofsolution, spin coating, coating from a latex, powder coating, laminatingpreformed films, spray coating molten droplets, and coating from themelt.

Various molding techniques may be used to form articles from thepolymers of the present invention. Powders, pellets, beads, flakes,reground material or other forms of rigid-rod and segmented rigid-rodpolyphenylenes may be molded, with or without liquid or other additives,premixed or fed separately. Rigid-rod and segmented rigid-rodpolyphenylene may be compression molded, the pressure and temperaturesneeded being dependent on the particular side groups present. Exactconditions may be determined by trial and error molding of smallsamples. Upper temperature limits may be estimated from thermal analysissuch as thermogravimetric analysis. Lower temperature limits may beestimated from T_(g) as measured for example by Dynamic MechanicalThermal Analysis (DMTA). Some suitable conditions for particular sidegroups are given in the examples below.

Some of the polymers provided in accordance with the present inventionmay also be injection molded. To determine if a particular polymer canbe injection molded it is necessary to measure the melt viscosity undershear, typically using a capillary melt flow rheometer. Typicallypolymers having melt viscosities of less than 10,000 poises at shearrates greater than 10³ sec⁻¹ can be injection molded. To be suitable forinjection molding, polymers must also remain fluid (ie. without gellingor solidifying) at the molding temperature during the molding operation.It is also desirable if the polymer can be remelted several timeswithout degradation, so that regrind from molding processes can be used.Particular examples of rigid-rod and segmented rigid-rod polyphenyleneswhich meet these requirements are given below. However, injectionmolding is not limited to the particular side groups shown, and theutility of injection molding for any of the polymers of the presentinvention may readily be determined by one skilled in the art.

Referring to FIG. 4, there is shown a schematic view of a radome 42molded from a rigid-rod or segmented rigid-rod polymer provided inaccordance with practice of the present invention. The radome 42 isshown mounted on the wing structure 44 of an aircraft. The radome isessentially a radar transparent cover which is structurallyself-supporting.

In addition to films and fibers, other forms of rigid-rod and segmentedrigid-rod polyphenylenes may be produced by extrusion. Non-limitingexamples include: angle, channel, hexagonal bar, hollow bar, I-beam,joining strip, rectangular tube, rod, sheet, square bar, square tube,T-section, tubes, or other shapes as is required for a particularapplication. Related to extrusion is pultrusion, wherein a fiberreinforcement is continuously added to an extruded polymer. The polymersof the present invention may be used as a thermoplastic matrix which ispultruded with fibers, such as carbon fiber or glass fiber.Alternatively, the polymers of the present invention may be used as thefiber for pultrusion of a thermoplastic having a lower processingtemperature. In the first case, composites with exceptional moduli andcompressive strength will result. In the second case, lower costthermoplastics having moderate moduli and strength can be formed intocomposites with high moduli and strength by the incorporation ofrigid-rod or segmented rigid-rod polyphenylene fibers. Such a compositeis unique in that the reinforcing fibers are themselves thermoplasticand further processing at temperatures above the fiber T_(g) will resultin novel structures as the fibers physically and/or chemically mix withthe matrix.

Many of the forms of rigid-rod and segmented rigid-rod polyphenylenesalluded to above, i.e., fiber, film, sheet, rod, etc., may be furtherprocessed and combined with other material to yield articles of highervalue. Sheet stock may be cut, stamped, welded, or thermally formed. Forexample, printed wiring boards may be fabricated from sheet or thickfilms by a process wherein copper is deposited on to one or both sides,patterned by standard photolithographic methods, etched, then holes aredrilled, and several such sheets laminated together to form a finishedboard. Such boards are novel in that they do not contain any fiberreinforcement. Such reinforcement is not necessary because of theunusually high modulus of the instant polymers. Such boards are alsounique in that they may be bent into non-planar structures, byapplication of heat and pressure, to better fit limited volumeenclosures, such as laptop computers. Sheet and film may also bethermoformed into any variety of housings, cabinets, containers, covers,chassis, plates, panels, fenders, hoods, and the like.

Referring to FIG. 5, there is shown a semi-schematic cross-sectionalside view of a four-layer wiring board 50. The board is comprised ofrigid-rod or segmented rigid-rod polymer dielectric 52. Copper lines 54are embedded in the dielectric 52 to form the inner two circuit planes.Copper lines 56 on the surface of the board form the two outer circuitplanes. A via 58 is used to connect conducting lines in differentplanes. The via 58 connects conducting lines in the two outer planeswith the line in one of the inner planes. The dielectric 52 can be apure rigid-rod polymer, a segmented rigid-rod polymer, a blend, alaminate or fiber-containing composite.

Referring to FIG. 6, there is shown a non-woven mat 60 which consists ofchopped fibers 62 comprised of a rigid-rod or segmented rigid-rodpolymer provided in accordance with practice of the present invention.Such non-woven mats may be used as filters or the like.

Referring to FIG. 7, there is shown a block of foam 70 comprising arigid-rod or segmented rigid-rod polymer provided in accordance withpractice of the present invention.

Rigid-rod and segmented rigid-rod polyphenylenes may also form thedielectric layers of multichip modules. Multichip modules (MCM) aresimilar to printed wiring boards except that integrated circuits aremounted directly on the MCM without prior packaging. The integratedcircuits may be more closely packed, saving total system volume,reducing propagation delays, and increasing maximum operating frequency,among other benefits. The basic structure of a multichip module is shownin FIG. 8. There are alternating layers of dielectric and currentcarrying conducting lines. Means for electrically and physicallyattaching integrated circuits is provided, as well as interconnection tothe next highest level of packaging. Such MCM structures may befabricated by many diverse processes. Because the rigid-rod andsegmented rigid-rod polyphenylenes of the present invention both meltand dissolve in common solvents any of the currently practiced methodsof MCM fabrication may be applied.

Referring to FIG. 8, a semi-schematic cross-sectional side view of anMCM, provided in accordance with practice of the present invention isshown. The MCM is typically (but not necessarily) fabricated usingphotolithographic techniques similar to those used in integrated circuitfabrication. As a non-limiting example an MCM may be constructed by spincoating a layer 82 of rigid-rod or segmented rigid-rod polyphenyleneonto a silicon substrate 84, having a plurality of resistors 86 on itssurface, to thereby form a dielectric layer. The polyphenylene layer 82may be further cured thermally or chemically if necessary. A layer ofcopper 88 is deposited onto the polyphenylene layer, and a layer ofphotoresist (not shown) is deposited, exposed, developed and theunderlying copper etched through the developed pattern in the resist. Asecond layer 90 of rigid-rod or segmented rigid-rod polyphenylene isspin coated and cured. Vias (not shown) to the underlying copper linesare cut, for example by laser drilling. Additional layers of copper 92and dielectric 94 are added and patterned. Completed MCM's may have sixor more alternating layers depending on the circuit complexity. Thedielectric for MCM's may also be fabricated by laminating films, byspray coating or by other methods known in the art. The rigid-rod orsegmented rigid-rod polyphenylene layer itself may be photosensitive,allowing additional methods of processing. Photosensitivity of therigid-rod or segmented rigid-rod polyphenylene will depend on the sidegroup and addition of catalysts and sensitizers.

The polymers of the present invention may also be combined with avariety of other polymers, additives, fillers, and the like,collectively called additives, before processing by any of the above orother methods. For example, the polymers of the present invention may beblended with some amount of a more flexible polymer to improve theextension-to-break of the blend. Thus, finished products formed fromsuch a blend, e.g., film, sheet, rod or complex molded articles will berelatively tougher. Rubbers may be added to toughen the finishedproduct. A liquid crystalline polymer may be added to reduce meltviscosity. Many other combinations will be apparent to those skilled inthe art. The particular amounts of each additive will depend on theapplication but may cover the range from none (pure rigid-rod orsegmented rigid-rod polyphenylene) to large amounts. As the amount ofadditives becomes much larger than the amount of rigid-rod polyphenylenethe rigid-rod polyphenylene itself may be considered an additive.

Polymers comprising the rigid-rod and segmented rigid-rods of thepresent invention can also be used in structural applications. Becauseof their high intrinsic stiffness, parts fabricated with rigid-rod orsegmented rigid-rod polymers will have mechanical properties approachingor equal to fiber containing composites. In many applications wherefibers are necessary for structural reasons they cause other undesirableeffects. For example, radomes for airborne radar are typicallyconstructed of glass fiber reinforced composites, but the glass fiberslead to signal loss and degradation of radar performance. Fiberlessradomes comprised of rigid-rod or segmented rigid-rod polymers wouldimprove radar performance over composite radomes. Fiberless radomeswould also be easier to fabricate than composite radomes. Fiberlessradomes comprising rigid-rod or segmented rigid-rod polymers provided inaccordance with the present invention could be injection or compressionmolded or stamped from sheet, or machined from stock.

Rigid-rod and segmented rigid-rod polymers can also be used to advantagein fiber containing composites as the matrix resin. As is known in theart the compressive strength of composites is related to the modulus ofthe matrix resin. Referring to FIGS. 9 and 9A, a composite 100comprising reinforcing fibers 102 and 104 in the plane of the compositesurface is shown. The fibers 102 run in a direction perpendicular to thefibers 104. Resins with high moduli will give composites with highcompressive strength. The polymers of the present invention can be usedto form composites by any of the established techniques, such assolution or powder impregnating (prepregging) fiber tows, yarns, tapesand fabrics, followed by lay-up of the prepregs to the desired shapewith a mold or form, and consolidating the composite by application ofheat and pressure. Additives may be used as is known in the artincluding mold releases, antioxidants, curing agents, particulates,tougheners and the like.

Non limiting examples of additives which may be used with rigid-rod orsegmented rigid-rod polyphenylenes are: adhesion promoters,antioxidants, carbon black, carbon fibers, compatibilizers, curingagents, dyes, fire retardants, glass fibers, lubricants, metalparticles, mold release agents, pigments, plasticizers, rubbers, silica,smoke retardants, tougheners, UV absorbers, and the like.

The rigid-rod and segmented rigid-rod polymers of the present inventionmay be used as additives to modify the properties of other polymers andcompositions. Relatively small amounts of the polymers of the presentinvention will significantly increase the mechanical properties offlexible polymers. Addition of about 5% of the polymer 1 to a blend ofpolystyrene and polyphenylene oxide increases the tensile modulus byabout 50%. The polyphenylenes of the present invention may be added toany other polymer. The degree of improvement of mechanical propertieswill depend on the properties of the other polymer without the addedpolyphenylene, on the amount of polyphenylene used, on the degree towhich the polyphenylene is soluble in the other polymer, and on theamounts and types of additives or compatibilizers.

In general, polymers of differing types do not mix. There are manyexceptions to this rule and many pairs of completely miscible polymersare known. For most of these miscible polymers specific interactionsresult in a negative heat of mixing, for example, hydrogen bonding, orionic interactions. Polymer pairs which are not miscible can often bemade miscible by addition of a third polymer, typically a low MWcopolymer having segments similar to the polymers to be blended. Use ofthese and other types of compatibilizers are known in the art. Thesetechniques may be applied to the rigid-rod and segmented rigid-rodpolyphenylenes of the present invention to enhance their utility asadditives. Thus a copolymer having segments which interact strongly witha rigid-rod polyphenylene as well as segments which interact stronglywith a second polymer will act as a compatibilizer for the two. Smallermolecules such as NMP, triphenylphosphate, and diphenylether will alsoaid compatibility by solvating the polyphenylenes of the presentinvention. It will also be apparent to one skilled in the art that theparticular side group on the rigid-rod or segmented rigid-rodpolyphenylene will strongly influence its ability to blend. In generalthe side group should be chosen so that there is a negative heat ofmixing between the side group and the polymer in which it must mix. Itshould also be apparent that complete miscibility is not alwaysrequired. Blending often results in mixing on a microscopic, but notmolecular, level. Such blends will have properties different than thepure polymers and are often desirable. Even blends with macroscopicphases may have utility and may be considered another form of composite.

Rigid-rod and segmented rigid-rod polyphenylenes will be particularlyuseful as additives for flame retardants, smoke retardants, tougheners,or to control or enhance creep resistance, coefficient of thermalexpansion, viscosity, modulus, tensile strength, hardness, moistureresistance, gas permeability, and abrasion resistance.

GENERAL PROCEDURES

1. 2,5-dichlorobenzoyl-containing compounds

A wide variety of 2,5-dichlorobenzoyl-containing compounds (e.g.2,5-dichlorobenzophenones and 2,5-dichlorobenzamides) can be readilyprepared from 2,5-dichlorobenzoylchloride. Pure2,5-dichlorobenzoylchloride is obtained by vacuum distillation of themixture obtained from the reaction of commercially available2,5-dichlorobenzoic acid with a slight excess of thionyl chloride inrefluxing toluene. 2,5-dichlorobenzophenones (e.g.2,5-dichlorobenzophenone, 2,5-dichloro-4'-methylbenzophenone,2,5-dichloro-4'-methoxybenzophenone, and2,5-dichloro-4'-phenoxybenzophenone) are prepared by the Friedel-Craftsbenzoylations of an excess of benzene or substituted benzenes (e.g.toluene, anisole, or diphenyl ether, respectively) with2,5-dichlorobenzoylchloride at 0°-5° C. using 2-3 mole equivalents ofaluminum chloride as a catalyst. The solid products obtained uponquenching with water are purified by recrystallization fromtoluene/hexanes. 2,5-dichlorobenzoylmorpholine and2,5-dichlorobenzoylpiperidine are prepared from the reaction of2,5-dichlorobenzoylchloride and either morpholine or piperidine,respectively, in toluene with pyridine added to trap the hydrogenchloride that is evolved. After washing away the pyridinium salt and anyexcess amine, the product is crystallized from the toluene solution.

2. Activated Zinc Powder

Activated zinc powder is obtained after 2-3 washings of commerciallyavailable 325 mesh zinc dust with 1 molar hydrogen chloride in diethylether (anhydrous) and drying in vacuo or under inert atmosphere forseveral hours at about 100°-120° C. The resulting powder should besifted (e.g. a 150 mesh sieve seems to be satisfactory), to remove thelarger clumps that sometimes form, to assure high activity. Thismaterial should be used immediately or stored under an inert atmosphereaway from oxygen and moisture.

The following specific examples are illustrative of the presentinvention, but are not considered limiting thereof in any way.

EXAMPLE 1 Poly-1,4-(benzoylphenylene)

Anhydrous bis(triphenylphosphine) nickel(II) chloride (34.7 g; 53mmole), triphenylphosphine (166.6 g; 741 mmole), sodium iodide (34.6 g,231 mmole), and 325 mesh activated zinc powder (181.8 g, 2.8 mole) wereweighed into a bottle under an inert atmosphere and added to an ovendried 12-liter flask, containing 1.6 liters of anhydrousN-methylpyrrolidinone (NMP), against a vigorous nitrogen counterflow.This mixture was stirred for about 15 minutes, leading to a deep-redcoloration. Solid 2,5-dichlorobenzophenone (466 g, 1.86 mol) and another0.8 liters of anhydrous NMP were then added to the flask. After aninitial slight endotherm (due to dissolution of monomer), thetemperature of the vigorously stirred reaction mixture warmed to about60° C. over 30 minutes and was held there (60°-65° C.) by use of acooling bath. After stirring for an additional 10-15 minutes, theviscosity of the reaction mixture increased drastically and stirring wasstopped. After heating this mixture for several days at 65° C., theresulting viscous solution was poured into 10 L of 1 molar hydrochloricacid in ethanol to dissolve the excess zinc metal and to precipitate themacromonomer. This suspension was filtered and the precipitatetriturated with acetone and dried to afford 283 g (85% yield) of a finepale-yellow powder.

The sample was found to have an intrinsic viscosity of 7.2 dL/g in 0.05molar lithium bromide in NMP at 40° C. GPC analysis indicated a weightaverage molecular weight, relative to narrow polydispersity polystyrenestandards, of 550,000-600,000.

EXAMPLE 2 Poly-1,4-(4'-phenoxybenzoylphenylene)2,5-Dichloro-4'-phenoxybenzophenone

To a 22 L open-mouth round bottom flask fitted with a three-neckedflange head, a mechanical stirrer, a nitrogen inlet and an outletconnected to a HCl scrubbing tower was added 2,5-dichlorobenzoicchloride (4500 g, 21.5 mol) and phenyl ether (5489 g, 32.3 mol). Thesolution was cooled in ice to 5° C. under stirring and aluminum chloride(3700 g, 27.8 mol) was added slowly. After about 300 g aluminum chloridewas added, the solution started to foam violently. The rest was addedcarefully over about 10 min. On several occasions, the stirring had tobe stopped to control the foaming. The temperature of the reactionmixture was about 35° C. after the addition. The mixture was thenstirred for about 30 min. and poured into about 20 gallon of ice water.The large reddish mass was dissolved by adding about 12 L of methylenechloride and stirring. The organic layer was separated and the aqueouslayer was extracted with some methylene chloride. After methylenechloride was removed from the combined organic layer by distillation,the residue was recrystallized twice from cyclohexane (2×10 L), washedwith cooled hexane, air dried and then vacuum dried to afford 5387 gmonomer (73%). The mother liquor was kept for later recovery ofremaining product.

Poly-1,4-(4'-phenoxybenzoylphenylene)

To a 12 L open-mouth round bottom flask equipped with a flange head, anair driven stirrer, a thermowell with a thermocouple, and a nitrogenpurge line, was added under nitrogen bis(triphenylphosphine)nickel(II)chloride (58.2 g, 88.9 mmol), sodium iodide (54.7 g, 365 mmol),triphenylphosphine (279.3 g, 1065 mmol), 325 mesh activated zinc dust(239.5 g, 3663 mmol) and anhydrous N-methylpyrrolidinone (NMP) (3400ml). The solution was stirred and heated with a hot air gun to 40° C.The monomer 2,5-dichloro-4'-phenoxybenzophenone (935 g, 2725 mmol) wasadded. The temperature dropped to 36.3° C. and then climbed to about 65°C. when an ice water bath was used to control the temperature below 86°C. After about 15 min. the mixture became viscous. After 17 min. thesolution became very thick and the stirring was stopped. The reactionmixture was allowed to come to room temperature and was left to standovernight. The next morning the reaction mixture was coagulated into anacetone bath and ground up in a blender. The crude polymer was thenstirred for several days in 1 molar hydrochloric acid in ethanol toremove the excess zinc metal. The polymer was collected by filtration,washed with water and acetone and dissolved in 16 L of methylenechloride. The solution was filtered through 10 um polypropylene membranewith the aid of celite, coagulated in the same volume of acetone,filtered, extracted with acetone for three days and dried to afford 700g pale yellow polymer (94%). GPC analysis showed a weight averagemolecular weight of 653,000 with the polydispersity being 1.97, relativeto polystyrene standard.

EXAMPLE 3Poly-1,4-(2-[2-(2-methoxyethoxy)ethoxy]ethoxycarbonyl)phenylene2-[2-(2-Methoxyethoxy)ethoxy]ethyl 2,5-dichlorobenzoate(Triethyleneglycol 2,5-dichlorobenzoate)

To a round bottom flask fitted with a Dean-Steak water separationapparatus, a magnetic stirrer and a condenser were added2,5-dichlorobenzoic acid (20 g, 0.11 mol), triethylene glycolmonomethylether (30 ml, 0.17 mol), concentrated sulfuric acid (0.4 ml)and benzene (100 ml). The mixture was refluxed for 3 days and about 1.8ml of water was collected. The solution was cooled to room temperatureand the solvent was removed on a rotary evaporator. The residue wasdiluted with ether and washed with diluted aqueous sodium bicarbonate,washed with brine, and dried with magnesium sulfate. The liquid obtainedafter the removal of solvent was purified by filtration through about 5g of basic alumina, with methylene chloride as the eluent. The fraction,after distillation of solvent, was dried under vacuum overnight withstirring to afford 30.8 g of pure ester (88%).

Poly-1,4-(2-[2-(2-methoxyethoxy)ethoxy]ethoxycarbonyl)phenylene

Into a 100 ml round bottom flask containing NMP (7.5 ml) were weightedin a glove box anhydrous nickel(II) chloride (30 mg, 0.23 mmol), sodiumiodide (125 mg, 0.83 mmol), triphenylphosphine (0.5 g, 1.91 mmol),activated zinc dust (0.65 g, 10.16 mmol). This mixture was stirred witha magnetic stirrer for 40 min. at 50° C., leading to a deep redsolution. Monomethylated triethyleneglycol 2,5-dichlorobenzoate (2.8 g,7.95 mmol) was added as a neat liquid with a syringe. The mixture wasstirred at this temperature for 3 days, resulting a viscous solution.Ethanol (100 ml) was added. A suspension was obtained after stirring. Itbecame a clear and almost colorless solution when 10 ml of 36%hydrochloric acid was added. The solution then was neutralized withdiluted aqueous sodium hydroxide. The resulting suspension containinggel-like polymer was extracted with methylene chloride. The organiclayer was filtered and concentrated. The polymer was precipitated withethanol, separated by using a centrifuge and dried under vacuum. Awhite, gum-like solid was obtained (1.48 g, 67%). The weight averagemolecular weight, relative to polystyrene standard, was 116,000according to GPC analysis.

EXAMPLE 4 Poly-1,4-(3'-methylbenzoylphenylene)2,5-Dichloro-3'-methylbenzophenone

A mixture of m-toluoyl chloride (22 g, 0.17 mol) and 1,4-dichlorobenzene(120 g, 0.82 mol) was heated to 100° C. in a flask. Aluminum chloride(60 g, 0.45 mol) was added in one portion. Hydrogen chloride started toevolve from the solution. The mixture was heated to 170° C. in 30 min.and stirred at this temperature for 3 hours. The resulting brownishsolution was cooled to about 80° C. and poured onto ice. Ether (50 ml)was added. The organic layer was separated and distilled under vacuumafter the removal of ether. The residue from distillation wasrecrystallized twice from hexane to give 20 g of white crystals (53%).

Poly-1,4-(3'-methylbenzoyl)phenylene

Anhydrous nickel(II) chloride (60 mg, 0.47 mmol), sodium iodide (175 mg,1.17 mmol), triphenylphosphine (0.75 g, 2.86 mmol), activated zinc dust(2.3 g, 35.9 mmol) were weighed in a glove box into a 100 ml roundbottom flask containing NMP (8 ml). This mixture was stirred with amagnetic stirrer for 30 min. at 50° C., leading to a deep red solution.A solution of 2,5-dichloro-3'-methylbenzophenone (2.6 g, 9.85 mmol) inNMP (7 ml) was added. A viscous solution was obtained after stirring for40 minutes. The mixture was kept at this temperature for another 10hours and then at 65° C. for another 3 days. Ethanol was added to thereaction mixture. The solid was moved into a blender, ground into smallpieces and then stirred with 50 ml of 1 molar hydrochloric acid inethanol for 2 hours. The off-white solid was filtered and stirred withacetone overnight. Filtration and vacuum drying gave 1.62 g off-whitepowder (85%). The weight average molecular weight, relative topolystyrene standard, was 139,000 according to GPC analysis.

EXAMPLE 5 Melt extrusion of Poly-1,4-(4'-phenoxybenzoylphenylene)

Poly-1,4-(4'-phenoxybenzoylpheneylene) provided in accordance withExample 2 is dried to constant weight in a vacuum oven at 170° C. Thedry polymer is loaded into the hopper of a twin screw extruder withinlet and barrel temperature set to 270° C.

In a first extrusion run, the extruder is fitted with a heated diehaving a 50 cm by 2 mm slit. The extruded sheet is air cooled and cutinto 50 cm lengths. The sheet stock is thermoformed by pressing betweenshaped platens of a steel mold at 250° C. and 500 psi.

In a second extrusion run, the extruder is fitted with a heated diehaving a 10 cm by 0.2 mm slit. The extruded film is passed through atrain of heated rollers and then abruptly accelerated between tworollers of different speeds to stretch the film by about 500%. Additionheat may be applied to keep the film above its T_(g) (about 160° C.) byradiant heating. The stretched film is annealed and cooled on a furtherroller train and collected as a continuous roll.

In a third extrusion run, the extruder is fitted with a die having 500spinnerets, each 200 microns in diameter at the exit. The polymer isextruded through the die and the multifilaments allowed to air coolbefore being collected on a windup bobbin.

In a fourth extrusion run, the extruder is fitted with a die having 200spinnerets, each 400 in diameter microns at the exit. The extrudedfilaments are pulled away from the exit at high velocity resulting in adraw ratio of about 12. The oriented fiber is collected on a windupbobbin.

In a fifth extrusion run, the extruder is fitted with a die suitable forextrusion of 1/2 inch pipe having 1/16 inch wall thickness. The pipe iscut into 4 foot lengths.

EXAMPLE 6 Production of Angle Stock ofpoly-1,4-(4'-phenoxybenzoylphenylene)

A blend of poly-1,4-(4'-phenoxybenzoylphenylene) provided in accordancewith Example 2, 200 g, polystyrene, 1000 g, and triphenylphosphate, 100g is loaded into the hopper of a single screw extruder. The blend isextruded through a die having an L shaped slit 1 inch by 1 inch by 3/16inch to produce angle stock.

EXAMPLE 7 Production of Fibers of poly-1,4-(4'-phenoxybenzoylphenylene)

50 g of poly-1,4-(4'-phenoxybenzoylphenylene) provided in accordancewith Example 2 is dissolved in a mixture of NMP, 25 ml, and methylenechloride, 425 ml by stirring for 48 hours. The viscous solution ispumped through a 0.2 mm orifice.

In the first run, the orifice is submerged at one end of a one metertrough containing 95% ethanol. The solution coagulates as it is injectedinto the ethanol. The coagulated polymer is manually pulled through thetrough to the end opposite the orifice where it is threaded throughrollers and attached to a take up spool. The speed of the take up spoolis regulated to provide a constant tension to the fiber.

In the second run, the orifice is held one centimeter from the surfaceat one end of a trough containing 95% ethanol. The solution is forcedthrough the orifice as a fine jet directed downward. The solutioncoagulates as it impinges on the ethanol. The coagulating fiber is fedaround a roller and across the trough to the opposite end where it iscollected on a constant tension take up roll.

EXAMPLE 8 Coating a Silicon Wafer withpoly-1,4-(4'-phenoxybenzoylphenylene)

50 g is of poly-1,4-(4'-phenoxybenzoylphenylene) dissolved in a mixtureof NMP, 25 ml, and methylene chloride 425 ml by stirring for 48 hours. A4" silicon wafer is coated with a thin film ofpoly-1,4-(4'-phenoxybenzoylphenylene) by spin coating the solution at300 rpm for 15 sec followed by 1500 rpm for 60 sec. The coated wafer isfurther dried in a 100° C. vacuum oven for 6 hrs.

EXAMPLE 9 Melt Spray Coating with poly-1,4-(4'-phenoxybenzoylphenylene)

A blend of poly-1,4-(4'-phenoxybenzoylphenylene) 50 g, and polystyrene,400 g are loaded into the heated reservoir of a spray gun. The moltenblend is forced by compressed nitrogen through the gun nozzle to form acoarse spray. The spray is directed such that a metal part is uniformlycovered with polymer. The coated part may be heated further in an ovento level the polymer coating.

EXAMPLE 10 Powder Prepregging with poly-1,4-(4'-phenoxybenzoylphenylene)

Poly-1,4-(4'-phenoxybenzoylphenylene) provided in accordance withExample 2 is prepared as a powder having average particle size of about10 microns. The powder is placed at the bottom of a closed chamberhaving a means to stir the powder. Carbon fiber tow is drawn through thechamber whereupon the stirred powder forms a dust cloud which adheres tothe carbon fibers. On leaving the powder chamber the coated carbonfibers then pass through a 150° C. oven to fix the polymer powder. Theresulting prepreg may be used to form composites by further forming andprocessing under heat and pressure.

EXAMPLE 11 Composite Fabrication with Prepreg frompoly-1,4-(4'-phenoxybenzoylphenylene)

The prepreg of Example 10 is wound onto a cylindrical tool. Heat andpressure are applied as the prepreg tow contacts the cylinder surface soas to consolidate the polymer powder. The cylinder is completely woundwith six layers of prepreg. During this operation the new layers arebonded to the underlying layers with local application of heat andpressure. This on-line consolidation allows large parts to be fabricatedwithout the use of an autoclave.

EXAMPLE 12 Comingled Filament Winding withpoly-1,4-(4'-Dhenoxybenzoylphenylene) Fibers

The fiber tow of the fourth extrusion run of Example 5 is co-mingledwith carbon fiber tow having 500 filaments and wound on a bobbin. Theresulting tow is used to filament wind a nosecone. The nosecone and toolare placed in a 200° C. oven for 1 hour to consolidate the polymerfilaments.

EXAMPLE 13 Pultrusion with Rigid-Rod Polyphenylene Fibers

The fiber tow of the fourth extrusion run of Example 5 is continuouslypulled through a polyetheretherketone melt and co-extruded through a dieto form ribbed panels.

EXAMPLE 14 Blow Molding of a polycarbonatepoly-1,4-(4'-phenoxybenzoylphenylene) Blend

A 90:10 blend of polycarbonate and poly-1,4-(4'-phenoxybenzoylphenylene)provided in accordance with Example 2 is used in an injection blowmolding machine to produce 1 liter bottles. In the process a parison isformed by an injection molding operation, the parison is then moved to amold and inflated to fill the mold. After cooling the finished bottle isremoved from the mold.

EXAMPLE 15 Poly-1,4-(4'-phenoxybenzoylphenylene)

Anhydrous bis(triphenylphosphine) nickel(II) chloride (102 g; 0.16mole), triphenylphosphine (408 g; 1.56 mole), sodium iodide (96 g, 0.64mole), and 325 mesh activated zinc powder (420 g, 6.42 mole) wereweighed into a bottle under an inert atmosphere and added to an ovendried 22-liter flask, containing 4 liters of anhydrous NMP, against avigorous nitrogen counterflow. This mixture was stirred for about 15minutes, leading to a deep-red coloration. Solid2,5-dichloro-4'-phenoxy-benzophenone and another 2 liters of anhydrousNMP were then added to the flask. After an initial slight endotherm (dueto dissolution of monomer), the temperature of the vigorously stirredreaction mixture warmed to about 85° C. over 15-20 minutes and was heldthere by use of a cooling bath. After stirring for an additional 10-15minutes, the viscosity of the reaction mixture increased drastically andstirring was stopped. After cooling the reaction mixture to roomtemperature overnight, the resulting viscous solution was coagulatedinto 25 L of 1 molar hydrochloric acid in ethanol to dissolve the excesszinc metal and to precipitate the polymer. This suspension was filtered,and the precipitate was continuously extracted with ethanol and thenwith acetone and dried.

To achieve high purity, the crude polymer was dissolved in about 35liters of NMP, pressure filtered through 1.2 micron (nominal)polypropylene fiber filters, coagulated into about 70 liters of acetone,continuously extracted with acetone, and dried to afford 1,186 g (91%yield) of a fine pale-yellow powder.

The sample was found to have an intrinsic viscosity of 5.0 dL/g in 0.05molar lithium bromide in NMP at 40° C. GPC analysis indicated a weightaverage molecular weight, relative to narrow polydispersity polystyrenestandards, of 450,000-500,000.

EXAMPLE 16 Copoly-{1,4-(benzoylphenylene)}-{1,3-phenylene}

Anhydrous bis(triphenylphosphine) nickel(II) chloride (10 g; 15 mmole),triphenylphosphine (50 g; 0.19 mole), sodium iodide (12 g, 80 mmole),and 325 mesh activated zinc powder (60 g, 0.92 mole) were weighed into abottle under an inert atmosphere and added to an oven dried 2-literflask, containing 800 milliliters of anhydrous NMP, against a vigorousnitrogen counterflow. This mixture was stirred for about 15 minutes,leading to a deep-red coloration. A mixture of 2,5-dichlorobenzophenone(127 g; 0.51 mole) and 1,3-dichlorobenzene (11 ml; 96 mmole) was thenadded to the flask. After an initial slight endotherm (due todissolution of monomer), the temperature of the vigorously stirredreaction mixture warmed to about 80°-85° C. over 30 minutes. Afterstirring for an additional 10-15 minutes, the viscosity of the reactionmixture increased drastically and stirring was stopped. After coolingthe reaction mixture to room temperature overnight, the resultingviscous solution was poured into 6 L of 1 molar hydrochloric acid inethanol to dissolve the excess zinc metal and to precipitate thepolymer. This suspension was filtered and the precipitate wascontinuously extracted with ethanol and then with acetone and dried toafford 93 g (94% yield) of crude white resin.

To achieve high purity, the crude polymer was dissolved in about 600 mLof methylene chloride, pressure filtered through 1.2 micron (nominal)polypropylene fiber filters, coagulated into about 2 liters of acetone,continuously extracted with acetone, and dried to afford 92 g (93%yield) of a fine white powder.

The sample was found to have an intrinsic viscosity of 1.75 dL/g in 0.05molar lithium bromide in NMP at 40° C. GPC analysis indicated a weightaverage molecular weight, relative to narrow polydispersity polystyrenestandards, of 150,000-200,000. DSC analysis indicated a glass transitiontemperature of 167° C.

EXAMPLE 17 Copoly-{1,4-(benzoylphenylene)}-{1,4-phenylene}

Anhydrous bis(triphenylphosphine) nickel(II) chloride (3.75 g; 5.7mmole), triphenylphosphine (18 g; 68.6 mmole), sodium chloride (2.0 g,34.2 mmole), 325 mesh activated zinc powder (19.5 g, 298 mmole), and 250mL of anhydrous NMP were weighed into an oven dried 1-liter flask underan inert atmosphere. This mixture was stirred for about 15 minutes,leading to a deep-red coloration. A mixture of 2,5-dichlorobenzophenone(45 g; 179 mmole) and 1,4-dichloro-benzene (2.95 g; 20 mmole) was thenadded to the flask. The temperature of the vigorously stirred reactionmixture was held at 60°-70° C. until the mixture thickened (about 30minutes). After cooling the reaction mixture to room temperatureovernight, the resulting viscous solution was poured into 1.2 L of 1molar hydrochloric acid in ethanol to dissolve the excess zinc metal andto precipitate the polymer. This suspension was filtered and theprecipitate was washed with acetone and dried to afford crude resin.

To achieve high purity, the crude polymer was dissolved in about 1.5 Lof NMP and coagulated into about 4 L of acetone, continuously extractedwith acetone, and dried to afford 30 g (89% yield) of an off-whitepowder.

The sample was found to have an intrinsic viscosity of 4.9 dL/g in 0.05molar lithium bromide in NMP at 40° C. GPC analysis indicated a weightaverage molecular weight, relative to narrow polydispersity polystyrenestandards, of 346,000. DSC analysis indicated a glass transitiontemperature of 167° C.

EXAMPLE 18 Preparation of Solvent Cast Thin Films of Rigid-RodPolyparaphenylenes of Examples 1 and 2.

Two methods are preferred for the preparation of good quality solventcast films of the polymers provided in accordance with Examples 1 and 2.All films are cast in a particle free, low humidity environment,preferably from filtered polymer solutions.

(a) The first method involves casting from solutions (about 1-15 weightpercent, preferably about 3-7 weight percent) in chloroform, anisole,dimethylacetamide (DMAc), N-methylpyrrolidinone (NMP), or other suitablesolvents. The solvent is evaporated, if low boiling, or removed in avacuum or convection oven, if high boiling. The films, especially thosethinner than about 1 mil, tend to be brittle but quite strong.

(b) A second method for preparing free-standing films involves castingfrom a solvent mixture of chloroform and NMP (generally containing about1-10 volume percent NMP, preferably about 1-2 volume percent). Polymerconcentrations typically range from about 1-15 weight percent,preferably about 3-7 weight percent. After casting the film, thechloroform quickly evaporates, leaving a highly NMP swollen(plasticized) but generally tack-free film. The remaining NMP can beeasily removed by heating in an oven to form the final dry film, whichtends to be quite optically transparent and colorless. Like thoseprepared from a single solvent, the completely dried films tend to bebrittle but strong.

The following film samples were prepared from batches of rigid-rodpolyparaphenylenes in Examples 1 and 15 with the specified intrinsicviscosities (related to molecular weight) according to the generalprocedures specified above and the conditions listed:

    ______________________________________                                        Sample                                                                              Polymer  Intrinsic                                                                              Film   Concen-                                        Identi-                                                                             of       Viscosity                                                                              Casting                                                                              tration                                        fication                                                                            Example  (dL/g)   Method (wt %) Solvent(s)                              ______________________________________                                        A     1        6.0      (a)    4.0    NMP                                     B     1        5.0      (b)    4.0    CHCl.sub.3 /NMP                         C     1        4.0      (b)    4.0    CHCl.sub.3 /NMP                         D     2        3.5      (b)    6.0    CHCl.sub.3 /NMP                         E     2        5.5      (b)    6.0    CHCl.sub.3 /NMP                         F     2        5.0      (a)    2.6    CHCl.sub.3                              ______________________________________                                    

The mechanical (tensile) properties of the resulting films (A-F) weremeasured in accordance with ASTM-D-882 standards. Standard test sampleswere prepared by carefully cutting the films to the desired size(approximately 6"×0.5"×0.001"). The films prepared by method (b) weremore easily cut (i.e. without microcracking along the edge of the teststrip) in their plasticized state. The average test results arepresented below:

    ______________________________________                                                   Tensile     Tensile                                                Sample     Strength    Modulus  Elongation                                    Identification                                                                           (ps)        (psi)    (%)                                           ______________________________________                                        A           7,000      1.0 × 10.sup.6                                                                   0.9%                                          B          31,000      2.4 × 10.sup.6                                                                   1.6%                                          C          30,000      1.1 × 10.sup.6                                                                   1.6-2.1%                                      D          18,500      0.9 × 10.sup.6                                                                   1.4-1.9%                                      E          30,000      1.0 × 10.sup.6                                                                   3.3                                           F          17,400      1.4 × 10.sup.6                                                                   1.3                                           ______________________________________                                    

EXAMPLE 19

The film of Example 18E is dried until it is approximately 5% by weightNMP. The NMP plasticized film is drawn through a set of rollers to givea draw ratio of 5 to 1. The oriented film may be further dried in vacuoat 100° C.

EXAMPLE 20 Compression Molding of Rigid-Rod Poly-1,4-(benzoylphenylene),Example 1 Material, and Poly-1,4-(4'-phenoxybenzoylphenylene), Example 2Material.

Coupons of the polymers provided in accordance with the procedures ofExamples 1 and 2 can be compression molded at relatively moderatetemperatures (200°-400° C.) and pressures (200-5,000 psi). Sometimessamples of the polymers of Examples 1 or 2 undergo darkening uponmolding at these temperatures, but the properties do not seem to beadversely affected. To obtain 2"×2"×0.1" panels of a batch of thepolymer of Example 1 (with an intrinsic viscosity of 4.0 dL/g) or thepolymer of Example 2 (with an intrinsic viscosity of 5.0 dL/g), the moldcavity is filled with about 8.0 g of resin and placed into an hydraulicpress preheated to the specified temperature. After holding the sampleat the molding temperature and molding pressure for the specifiedmolding time, the sample is cooled below at least about 100° C. duringthe cooling time while retaining the molding pressure. Upon cooling toambient temperature and removal from the mold, the following panels wereobtained according to the specified conditions:

    ______________________________________                                        Sample Polymer  Molding  Molding Molding                                                                              Cooling                               Identi-                                                                              of       Temp.    Pressure                                                                              Time   Time                                  fication                                                                             Example  (°C.)                                                                           (psi)   (minutes)                                                                            (hours)                               ______________________________________                                        G      1        250      1,800   20     5                                     H      1        300      2,500   20     5                                     I      1        350      1,800   20     5                                     J      2        350      1,250   30     3                                     ______________________________________                                    

The mechanical (flexural) properties of the resulting panels (G-J) weremeasured in accordance with ASTM-D-790 standards. Standard test Sampleswere prepared by carefully cutting the panels to the desired size (40mm×6 mm×2.6 mm). The test results are presented below:

    ______________________________________                                                   Flexural    Flexural Flexural                                      Sample     Strength    Modulus  Strain                                        Identification                                                                           (psi)       (psi)    (%)                                           ______________________________________                                        G          20,000      1.1 × 10.sup.6                                                                   1.9%                                          H          46,000      1.4 × 10.sup.6                                                                   4.2%                                          I          45,000      1.3 × 10.sup.6                                                                   4.2%                                          J          32,000      1.0 × 10.sup.6                                                                   3.8%                                          ______________________________________                                    

EXAMPLE 21 Sample Fabrication and Properties ofCopoly-{1,4-benzoylphenylene)}-{1,3-phenylene}.

A free-standing film, K, sample ofcopoly-{1,4-benzoylphenylene)}-{1,3-phenylene} ([η]=1.75 dL/g) wasprepared by conventional casting techniques from a 5.0% (wt/wt) solutionin chloroform. After drying, the mechanical (tensile) properties of thefilm were measured according to ASTM-D-882 specifications. A moldedcoupon (2"×2"×0.1"), L, ofcopoly-{1,4-benzoylphenylene)}-{1,3-phenylene} was prepared bycompression molding about 8.0 g of resin at 300° C. and 1,250 psipressure for 30 minutes and then cooling slowly (about 3 hours) toambient temperature while maintaining pressure. The mechanical(flexural) properties of the coupons were measured according toASTM-D-790 specifications; standard test samples were prepared bycarefully cutting the coupons to the desired size (40 mm×6 mm×2.5 mm).The following data was obtained for samples K and L:

    ______________________________________                                        Sample                                                                        identi-                                                                             Sample   Measurement                                                                              Strength                                                                              Modulus                                                                              Strain                               fication                                                                            type     Type       (psi)   (psi)  %                                    ______________________________________                                        K     Film     Tensile    26,000  1.1 × 10.sup.6                                                                 3.8                                  L     Coupon   Flexural   39,000  1.0 × 10.sup.6                                                                 7.7                                  ______________________________________                                    

EXAMPLE 22 Injection Molding of Rigid-RodPoly-1,4-(4'-phenoxybenzoyl-phenylene)

Complex parts of the polymer provided in accordance with the process ofExample 2 were injection molded by standard techniques at moderatetemperatures (280° C.). Mechanical (flexural) properties were measuredaccording to ASTM-D-790 specifications and melt viscosity was measuredat 280° C. with a melt rheometer with a capillary geometry of 10 mmlength and 1 mm diameter at a shear rate of 1,000/sec. The followingdata was obtained for injection molded strips of dimension 40 mmlength×6 mm width×1 mm thickness (MD, machine direction, refers tospecimens molded in the long direction (40 mm) to induce someorientation and TD, transverse direction, refers to specimens molded inthe short direction (6 mm) to minimize any orientation):

    ______________________________________                                        Sample Intrinsic                                                                              Melt     Flexural                                                                             Flexural                                                                              Flexural                              Identi-                                                                              Viscosity                                                                              Viscosity                                                                              Strength                                                                             Modulus Strain                                fication                                                                             (dL/g)   (poise)  (psi)  (psi)   %                                     ______________________________________                                        M-MD   5.5      9,600    41,000 1.9 × 10.sup.6                                                                  2.8                                   M-TD   5.5      9,600    33,000 1.2 × 10.sup.6                                                                  3.4                                   N-MD   3.5      6,400    36,000 2.1 × 10.sup.6                                                                  2.0                                   N-TD   3.5      6,400    25,000 1.3 × 10.sup.6                                                                  2.0                                   ______________________________________                                    

EXAMPLE 23 Preparation of Blends ofPoly-1,4-(4'-phenoxybenzoylphenylene) with Polybutylene Terephthalate(PBT) by Melt Extrusion/Injection Molding.

Blends of poly-1,4-(4'-phenoxy-benzoylphenylene)([η]=5.5 dL/g in 0.05MLiBr/NMP at 40° C.) and polybutylene terephthalate (e.g. NOVADUR PBTfrom Mitsubishi Kasei Corporation; [η]=1.1 dL/g in 1/11,1,2,2-tetrachloroethane/phenol) were prepared by conventional meltextrusion and test samples (40 mm length×6 mm width×1 mm thickness) wereobtained by injection molding at 280° C. Relative to samples preparedfrom pure polybutylene terephthalate, the blend samples typicallydemonstrated better flexural strength and modulus (ASTM-D-790) and shownbelow (MD, machine direction, refers to specimens molded in the longdirection (40 mm) to induce some orientation and TD, transversedirection, refers to specimens molded in the short direction (6 mm) tominimize any orientation):

    ______________________________________                                        Sample                                                                              Polypara- Melt     Flexural                                                                              Flexural                                                                             Flexural                              Identi-                                                                             phenylene Viscosity                                                                              Strength                                                                              Modulus                                                                              Strain                                fication                                                                            (wt %)    (poise)  (psi)   (psi)  (%)                                   ______________________________________                                        M-MD  100       9,600    41,000  1.9 × 10.sup.6                                                                 2.8                                   M-TD  100       9,600    33,000  1.2 × 10.sup.6                                                                 3.4                                   O-MD  40        2,200    12,000  0.4 × 10.sup.6                                                                 3.5                                   O-TD  40        2,200    10,400  0.4 × 10.sup.6                                                                 3.0                                   P-MD  20        1,050    12,600  0.3 × 10.sup.6                                                                 7.2                                   P-TD  20        1,050    12,200  0.3 × 10.sup.6                                                                 8.6                                   Q-MD  0         1,100    10,600  0.3 × 10.sup.6                                                                 13.3                                  Q-TD  0         1,100    10,300  0.2 × 10.sup.6                                                                 7.7                                   ______________________________________                                    

EXAMPLE 24 Preparation of Blends ofPoly-1,4-(4'-phenoxybenzoylphenylene) with Other Resins by Melt Mixing.

The polymer blends were prepared in a small (50 g) Brabender mixer (C.W.Brabender, Inc.; Hackensack, N.J.). The particular batch ofpoly-1,4-(4'-phenoxybenzoylphenylene) used for these experimentspossessed the following properties: [η]=3.5 dL/g (0.05M LiBr/NMP at 40°C.); M_(w) ^(GPC) =275,000; T_(g) (DSC)=143° C.; and melt viscosity (at300° C. and 1,000/sec shear rate)=4,100 poise. The mixer was preheatedto the temperature indicated below for the specified polymer to beblended with poly-1,4-(4'-phenoxybenzoylphenylene), and the resin wasadded slowly and allowed to achieve uniform melt consistence over about5 minutes. The poly-1,4-(4'-phenoxybenzoylphenylene) or a mixture ofpoly-1,4-(4'-phenoxybenzoylphenylene) and triphenylphosphate (TPP; usedas a plasticizer to lower the melt viscosity of the polyparaphenylene)was then added. If the blend was not uniform after about 5 minutes ofmixing, the temperature was increased to about 280°-300° C. for 5minutes. The mixer was then cooled to 165° C., and the blend was removedand allowed to cool to room temperature. The following blends wereprepared in this manner:

    ______________________________________                                        Sample               Polypara- Triphenyl                                                                            Initial                                 Identi-                                                                              Base          phenylene Phosphate                                                                            Temp.                                   fication                                                                             Resin         (wt %)    (wt %) (°C.)                            ______________________________________                                        PS-1   Polystyrene   0         10     175                                     PS-2   Polystyrene   5.0       10     175                                     PPO-1  Poly(phenylene oxide)                                                                       0.0       0      200                                     PPO-2  Poly(phenylene oxide)                                                                       10.0      0      200                                     NY-1   Nylon-6       0.0       0      220                                     NY-2   Nylon-6       10.1      0      220                                     ______________________________________                                         Polystyrene = HCC9100 from Hunter Chemical Co.; Poly(phenylene oxide) =       Noryl 731 from GE Plastics; Nylon6 (polycaprolactam) = DYLARK 232 from        ARCO Chemical.                                                           

Compression molded panels of the above blends were prepared formechanical (tensile) testing according to ASTM-D-638 standards bymolding at the temperature specified below at about 700 psi for 2minutes and then cooling to room temperature. The glass transitiontemperatures (T_(g)) were determined for the blends by dynamicmechanical thermal analysis (DMTA) of the compression molded parts.Specimens appropriate for DMTA and mechanical testing (sizeapproximately 6"×0.5"×0.1") were prepared from the molded panels byusing a band-saw and/or a router. The following data was obtained:

    ______________________________________                                        Sample   Molding  Tensile    Tensile                                                                              Glass                                     Identi-  Temp.    Strength   Modulus                                                                              Transition                                fication (°C.)                                                                           (psi)      (psi)  (T.sub.g /°C.)                     ______________________________________                                        PS-1     175      2,900      5.1 × 10.sup.5                                                                 89.5                                      PS-2     175      3,400      5.3 × 10.sup.5                                                                 91.5                                      PPO-1    175      7,100      2.6 × 10.sup.5                                                                 152                                       PPO-2    175      7,000      3.7 × 10.sup.5                                                                 155                                       NY-1     235      7,200      3.7 × 10.sup.5                                                                 226                                       NY-2     235      4,800      4.7 × 10.sup.5                                                                 225                                       ______________________________________                                    

EXAMPLE 25 Preparation of Blends of Poly-1,4-(benzoylphenylene) withOther Resins by Melt Mixing.

The polymer blends were prepared in a small (50 g) Brabender mixer (C.W.Brabender, Inc.; Hackensack, N.J.). The particular batch ofpoly-1,4-(benzoylphenylene) used for these experiments possessed thefollowing properties: [η]=3.5 dL/g (0.05M LiBr/NMP at 40° C.); M_(w)^(GPC) =300,000; and melt viscosity (at 300° C. and 100/sec shearrate)=27,000 poise. The mixer was preheated to the temperature indicatedbelow for the specified polymer to be blended withpoly-1,4-(benzoylphenylene), and the resin was added slowly and allowedto achieve uniform melt consistence over about 5 minutes. Thepoly-1,4-(benzoylphenylene) or a mixture of poly-1,4-(benzoylphenylene)and triphenylphosphate (TPP; used as a plasticizer to lower the meltviscosity of the polyparaphenylene) was then added. If the blend was notuniform after about 5 minutes of mixing, the temperature was increasedto about 280°-300° C. for 5 minutes. The mixer was then cooled to 165°C., and the blend was removed and allowed to cool to room temperature.The following blends were prepared in this manner:

    ______________________________________                                        Sample               Polypara- Triphenyl                                                                            Initial                                 Identi-                                                                              Base          phenylene Phosphate                                                                            Temp.                                   fication                                                                             Resin         (wt %)    (wt %) (°C.)                            ______________________________________                                        PS-1   Polystyrene   0.0       10     175                                     PS-3   Polystyrene   2.5       10     175                                     PS-4   Polystyrene   5.0       10     175                                     PPO-1  Poly(phenylene oxide)                                                                       0.0       0      200                                     PPO-3  Poly(phenylene oxide)                                                                       10.2      0      200                                     PP-1   Polypropylene 0.0       0      175                                     PP-2   Polypropylene 1.3       0      175                                     PP-3   Polypropylene 0.0       10     175                                     PP-4   Polypropylene 5.0       10     175                                     PE-1   Polyethylene  0.0       0      175                                     PE-2   Polyethylene  1.0       0      175                                     ______________________________________                                         Polystyrene = HCC9100 from Hunter Chemical Co.; Poly(phenylene oxide) =       Noryl 731 from GE Plastics; Polypropylene = Profax 6523 from Himont;          Polyethylene (high density) = # 8640 from Chevron.                       

Compression molded panels of the above blends were prepared formechanical (tensile) testing according to ASTM-D-638 standards bymolding at the temperature specified below at about 700 psi for 2minutes and then cooling to room temperature. The glass transitiontemperatures (T_(g)) were determined for the blends by dynamicmechanical thermal analysis (DMTA) of the compression molded parts.Specimens appropriate for DMTA and mechanical testing (sizeapproximately 6"×0.5"×0.1") were prepared from the molded panels byusing a band-saw and/or a router. The following data was obtained:

    ______________________________________                                        Sample   Molding  Tensile    Tensile                                                                              Glass                                     Identi-  Temp.    Strength   Modulus                                                                              Transition                                fication (°C.)                                                                           (psi)      (psi)  (T.sub.g /°C.)                     ______________________________________                                        PS-1     175      2,900      5.1 × 10.sup.5                                                                 92                                        PS-3     175      3,200      5.1 × 10.sup.5                                                                 90                                        PS-4     175      3,700      5.0 × 10.sup.5                                                                 91                                        PPO-1    175      7,100      2.6 × 10.sup.5                                                                 152                                       PPO-3    175      6,800      3.9 × 10.sup.5                                                                 155                                       PP-1     175      2,300      2.7 × 10.sup.5                                                                 155                                       PP-2     175      2,600      2.7 × 10.sup.5                                                                 157                                       PP-3     175      3,500      1.9 × 10.sup.5                                                                 155                                       PP-4     175      3,400      1.9 × 10.sup.5                                                                 158                                       PE-1     175      2,300      0.3 × 10.sup.5                                                                 N/A                                       PE-2     175      2,200      0.6 × 10.sup.5                                                                 N/A                                       ______________________________________                                    

EXAMPLE 26 Preparation of Blends of Poly-1,4-(benzoylphenylene) withPolystyrene by Solution Mixing.

The polymer blends were prepared by mixing solutions of each polymer inchloroform or a solvent mixture comprised of 90% (vol/vol) chloroformand 10% (vol/vol) NMP in proper proportion to achieve the compositionsspecified below. The particular batch of poly-1,4(benzoylphenylene) usedfor these experiments possessed the following properties: [η]=3.5 dL/g(0.05M LiBr/NMP at 40° C.); M_(w) ^(GPC) =300,000; and melt viscosity(at 300° C. and 100/sec shear rate)=27,000 poise. The polystyrene wasobtained from Hunter Chemical Co. (HCC9100). The blended resins wererapidly precipitated by pouring the co-solutions into methanol (3volumes relative to the volume of polymer co-solution). The precipitatewas filtered, washed with additional methanol, and dried under vacuumfor 24 hours at 70° C. compression molded panels of these blends wereprepared for mechanical (tensile) testing according to ASTM-D-638standards by molding at 175° C. at about 700 psi for 2 minutes and thencooling to room temperature. The glass transition temperatures (T_(g))were determined for the blends by dynamic mechanical thermal analysis(DMTA) of the compression molded parts. Specimens appropriate for DMTAand mechanical testing (size approximately 6"×0.5"×0.1") were preparedfrom the molded panels by using a band-saw and/or a router. Thefollowing data was obtained:

    ______________________________________                                        Sample          Polypara-                                                                              Tensile Tensile                                                                              Glass                                 Identi-         phenylene                                                                              Strength                                                                              Modulus                                                                              Transition                            fication                                                                            Solvent(s)                                                                              (wt %)   (psi)   (psi)  (T.sub.g /°C.)                 ______________________________________                                        PS-5  chloroform                                                                              0.0      2,100   4.9 × 10.sup.5                                                                 109                                   PS-6  chloroform                                                                              1.0      2,200   4.5 × 10.sup.5                                                                 N/A                                   PS-7  chloroform                                                                              5.0      2,400   4.8 × 10.sup.5                                                                 N/A                                   PS-8  chloroform                                                                              20.0     2,600   5.5 × 10.sup.5                                                                 115                                   PS-9  chloroform/                                                                             10.2     2,300   5.8 × 10.sup.5                                                                 110                                         NMP                                                                     ______________________________________                                    

EXAMPLE 27 Preparation of Blends ofPoly-1,4-(4'-phenoxybenzoylphenylene) with Polycarbonate by SolutionMixing.

The polymer blends were prepared by mixing solutions of each polymer inchloroform in proper proportion to achieve the compositions specifiedbelow. The particular batch of poly-1,4-(benzoylphenylene) used forthese experiments possessed the following properties: [η]=5.2 dL/g(0.05M LiBr/NMP at 40° C.) and M_(w) ^(GPC) =450,000. The polycarbonatewas obtained from Mitsubishi Kasei Corporation (NOVAREX polycarbonate).The blended solutions were then cast onto a glass plate and driedrapidly to afford transparent free-standing thin film samples. Thefollowing mechanical (tensile) properties were measured according toASTM-D-882 specifications:

    ______________________________________                                        Sample Polypara-                                                                              Tensile    Tensile                                            Identi-                                                                              phenylene                                                                              Strength   Modulus Elongation                                 fication                                                                             (wt %)   (psi)      (psi)   (%)                                        ______________________________________                                        PC-1   0        7,200      3.2 × 10.sup.5                                                                  8.6                                        PC-2   10       7,800      3.9 × 10.sup.5                                                                  3.4                                        PC-3   20       7,100      5.7 × 10.sup.5                                                                  1.6                                        PC-4   40       17,400     7.0 × 10.sup.5                                                                  2.0                                        PC-5   80       18,100     11.3 × 10.sup.5                                                                 1.9                                        PC-6   100      21,000     15.6 × 10.sup.5                                                                 1.8                                        ______________________________________                                    

EXAMPLE 28

Solutions containing 1.5 to 3 wt. % of poly-1,4-(benzoylphenylene)provided in accordance with Example 1 in Epomik R140 (Mitsui) wereprepared by stirring the polymer and the epoxy resin at 100°-140° C. Theresulting solutions were almost colorless. Both 1.5 and 3 wt % solutionswere very viscous at room temperature, however, the viscosity of thesolution dropped sharply with warming. To about 1 g of solution of thepolymer of Example 1 in Epomik R140 was added 6-12 drops ofethylenediamine (EDA). The resulting solution was mixed with a spatulauntil a homogeneous solution was obtained. The mixture was left to sitat room temperature to cure. Curing took from a few hours to two daysdepending on the amount of EDA. In all cases, a hard transparent masswas obtained. If the polymer mixture with EDA was heated to about 70° C.a very exothermic reaction occurred. The resulting cured polymer blendin this case was slightly turbid. Curing was also successful when asmall amount of NMP was used as plasticizer.

EXAMPLE 29 Determination of the Relative Coupling Reactivities ofMonohaloarene Model Compounds Using Nickel-Triarylphosphine Catalysts.

A mixture of 50 mg (0.39 mmole) of anhydrous nickel chloride, 175 mg(1.17 mmole) of sodium iodide, 750 mg (2.86 mmole) oftriphenylphosphine, 1.0 g (15.30 mmole) of activated zinc powder, 500 mg(2.17 mmole) of orthoterphenyl (used as an internal standard forchromatographic analysis), and 7 ml of NMP was placed into a flask underan inert atmosphere and heated at 50° C. for 10-15 minutes until themixture achieved a deep red coloration, indicative of an activatedcatalyst solution. Then approximately 19.3 mmole (50 mole equivalentsvs. anhydrous nickel chloride) of the desired monohaloarene modelcompound was added to the flask. The course of the reaction was thenfollowed by monitoring the disappearance of the monohaloarene modelcompound by standard quantitative gas chromatographic (GC) or highpressure liquid chromatographic (HPLC) techniques. Two simple approacheswere utilized to quantify the reactivities of the model compounds: (1)extent of reaction (conversion) of the model compound after two hoursand (2) the amount of time required to achieve at least 90% conversion.The first technique requires fewer measurements but can be stronglyaffected if there is any initiation period. The following data wasobtained by the above technique for the specified monohaloarene modelcompounds:

    ______________________________________                                        Monohaloarene Conversion   Time for                                           Model Compound                                                                              at 2 hrs     90% Conversion                                     ______________________________________                                        chlorobenzene >95%         30-40 min                                          2-chloroanisole                                                                              <5%         ≦23 hrs                                     3-chloroanisole                                                                             >90%         1.5-2.0 hrs                                        2-chlorobenzo-                                                                               ≦5%  N/A                                                trifluoride                                                                   3-chlorobenzo-                                                                              >95%         ≦1 hr                                       trifluoride                                                                   2-chlorobenzoyl-                                                                             5-10%       >40 hrs                                            morpholine                                                                    3-chlorobenzoyl-                                                                            ≧90%  1.5-2.0 hrs                                        morpholine                                                                    4-chlorobenzoyl-                                                                            50-60%       N/A                                                morpholine                                                                    2-chloroacetophenone                                                                        >95%         30 min                                             3-chloroacetophenone                                                                        >95%         30 min                                             2-chlorobenzophenone                                                                        >90%         2 hrs                                              3-chlorobenzophenone                                                                        60-80%       2.5-3.0 hrs                                        2-chlorophenyl-                                                                             10-15%       >24 hrs                                            acetate                                                                       ethyl-2-chlorobenzoate                                                                      <10%         >24 hrs                                            ______________________________________                                    

EXAMPLE 30 Poly-1,4-(2'-methylbenzoylphenylene)2,5-Dichloro-2'-methylbenzophenone

A mixture of o-toluoyl chloride (22 g, 0.17 mol) and 1,4-dichlorobenzene(120 g, 0.82 mol) was heated to 100° C. in a flask. Aluminum chloride(60 g, 0.45 mol) was added in one portion. The mixture was heated to170° C. in 30 min and stirred at this temperature for 3 hours. Theresulting brownish solution was cooled to about 80° C. and poured ontoice. Ether (50 ml) was added. The organic layer was separated anddistilled under vacuum after the removal of ether. The residue fromdistillation was recrystallized twice from hexane to give 16 g of whitecrystals (36%).

Poly-1,4-(2'-methylbenzoylphenylene)

Anhydrous nickel(II) chloride (60 mg, 0.47 mmol), sodium iodide (175 mg,1.17 mmol), triphenylphosphine (0.75 g, 2.86 mmol), activated zinc dust(2.3 g, 35.9 mmol) were weighted in a glove box into a 100 ml roundbottom flask containing NMP (8 ml). This mixture was stirred with amagnetic stirrer for 30 min at 50° C., leading to a deep red solution. Asolution of 2,5-Dichloro-2'-methylbenzophenone (10 mmol) in NMP (7 ml)was added. Stirring was continued for about 40 minutes until a viscoussolution was obtained. The mixture was kept at 65° C. for another 2-3days. Ethanol was added to the reaction mixture. The solid was movedinto a blender, ground into small pieces and then stirred with 50 ml of1 molar hydrochloric acid in ethanol for 2 hours. The off-white solidwas filtered and stirred with acetone overnight. Filtration and vacuumdrying gave off-white or pale yellow powder. The weight averagemolecular weight relative to polystyrene standard according to GPCanalysis was 70,000.

EXAMPLE 31 Poly-1,4-(2',5'-dimethylbenzoylphenylene)2,5-Dichloro-2',5'-dimethylbenzophenone

To p-xylene (120 ml, 0.98 mol) was added aluminum chloride (32 g, 0.24mol) at room temperature. To this mixture 2,5-dichlorobenzoyl chloride(30 g, 0.14 mol) was added slowly. The reaction was exothermic andhydrogen chloride evolved from the reddish solution. After the addition,the mixture was stirred for 10 min and then hydrolysed by slow additionof water. The aqueous layer was extracted with ether. The organic layerwas combined with ethereal extract and washed with water, saturatedsodium bicarbonate, brine, respectively, and then dried with magnesiumsulfate. After the removal of solvent, the residue was recrystallizedfrom methanol twice and then from hexane to give 36.8 g (92%) crystals(mp 58°-61° C.).

Poly-1,4-(2',5'-dimethylbenzoylphenylene)

Anhydrous nickel(II) chloride (60 mg, 0.47 mmol), sodium iodide (175 mg,1.17 mmol), triphenylphosphine (0.75 g, 2.86 mmol), activated zinc dust(2.3 g, 35.9 mmol) were weighted in a glove box into a 100 ml roundbottom flask containing NMP (8 ml). This mixture was stirred with amagnetic stirrer for 30 min at 50° C., leading to a deep red solution. Asolution of 2,5-Dichloro-2',5'-dimethylbenzophenone (10 mmol) in NMP (7ml) was added. Stirring was continued for about 40 minutes until aviscous solution was obtained. The mixture was kept at 65° C. foranother 2-3 days. Ethanol was added to the reaction mixture. The solidwas moved into a blender, ground into small pieces and then stirred with50 ml of 1 molar hydrochloric acid in ethanol for 2 hours. The off-whitesolid was filtered and stirred with acetone overnight. Filtration andvacuum drying gave off-white or pale yellow powder. The weight averagemolecular weight relative to polystyrene standard was 50,000 accordingto GPC analysis.

EXAMPLE 32 Poly-1,4-(2-(2-pyrrolidinon-1-yl)ethoxycarbonylphenylene)2-(2-Pyrrolidinon-1-yl)ethyl 2,5-dichlorobenzoate

A mixture of 2,5-dichlorobenzoic acid (20 g, 0.11 mol),1-(2-hydroxyethyl-2-pyrrolidinone (27 g, 0.22 mol) in benzene (100 ml)was refluxed in the presence of 1 ml of concentrate sulfuric acid for 24hours. About 2.2 ml of water was collected. The mixture was cooled andwashed with aqueous sodium bicarbonate and water, respectively andevaporated. The residue was purified by recrystallization from hexaneand ethyl acetate to give the esters as white crystals (10 g, 32%).

Poly-1,4-(2-(2-pyrrolidinon-1-yl)ethoxycarbonylphenyene)

Anhydrous nickel(II) chloride (60 mg, 0.47 mmol), sodium iodide (175 mg,1.17 mmol), triphenylphosphine (0.75 g, 2.86 mmol), activated zinc dust(2.3 g, 35.9 mmol) were weighted in a glove box into a 100 ml roundbottom flask containing NMP (8 ml). This mixture was stirred with amagnetic stirrer for 30 min at 50° C., leading to a deep red solution. Asolution of 2-(2-Pyrrolidinon-1-yl)ethyl 2,5-dichlorobenzoate (10 mmol)in NMP (7 ml) was added. Stirring was continued for about one week and aviscous solution was obtained. The mixture was kept at 65° C. foranother 2-3 days. Ethanol was added to the reaction mixture. The solidwas moved into a blender, ground into small pieces and then stirred with50 ml of 1 molar hydrochloric acid in ethanol for 2 hours. The off-whitesolid was filtered and stirred with acetone overnight. Filtration andvacuum drying gave off-white or pale yellow powder. The polymer hasstructure I with R₁₌ ##STR11## and R₂ -R₄ =H. The weight averagemolecular weight, relative to polystyrene standard according to GPCanalysis was 72,000.

EXAMPLE 33 Poly-1,4-(4'-(2-phenoxyethoxy)benzoylphenylene)2,5-Dichloro-4'-(2-phenoxyethoxy)benzophenone

To a suspension of 1,2-diphenoxyethane (25 g, 0.11 mol), aluminumchloride (14 g, 0.11 mol) in chlorobenzene (400 ml) was added slowly2,5-dichlorobenzoyl chloride (9.8 g, 0.05 mol) at 0° C. After theaddition, the mixture was stirred for another 20 minutes and worked upas usual. After the removal of solvent, the residue was purified bychromatography on silica gel and recrystallization from cyclohexane togive 9 g pure ketone (50%).

Poly-1,4-(4'-(2-phenoxyethoxy)benzoylphenylene)

Anhydrous nickel(II) chloride (60 mg, 0.47 mmol), sodium iodide (175 mg,1.17 mmol), triphenylphosphine (0.75 g, 2.86 mmol), activated zinc dust(2.3 g, 35.9 mmol) were weighted in a glove box into a 100 ml roundbottom flask containing NMP (8 ml). This mixture was stirred with amagnetic stirrer for 30 min at 50° C., leading to a deep red solution. Asolution of 2,5-Dichloro-4'-(2-phenoxyethoxy)-benzophenone (10 mmol) inNMP (7 ml) was added. Stirring was continued until a viscous solutionwas obtained, about 3 hours. The mixture was kept at 65° C. for another2-3 days. Ethanol was added to the reaction mixture. The solid was movedinto a blender, ground into small pieces and then stirred with 50 ml of1 molar hydrochloric acid in ethanol for 2 hours. The off-white solidwas filtered and stirred with acetone overnight. Filtration and vacuumdrying give off-white or pale yellow powder. The weight averagemolecular weight relative to polystyrene standard was 218,000 by GPCanalysis.

The above descriptions of exemplary embodiments of processes forproducing rigid-rod and segmented rigid-rod polymers, and the rigid-rodand segmented rigid-rod polymers produced by the processes, are forillustrative purposes. Because of variations which will be apparent tothose skilled in the art, the present invention is not intended to belimited to the particular embodiments described above. The scope of theinvention is defined in the following claims.

We claim:
 1. A soluble rigid rod polymer having repeat units of theformula: ##STR12## wherein R₁ is a solubilizing side group havingmolecular weight of from about 15 to about 300, and wherein theintrinsic viscosity of said polymer is greater than about 3deciliters/gram when measured at 40° C. in a solvent selected from thegroup consisting of 0.05M lithium bromide in N-methylpyrrolidinone,N-methylpyrrolidinone, dimethylacetamide, phenylether, m-cresol,sulfuric acid, anisole, 5% N-methylpyrrolidinone/95% CHCl₃, andchlorobenzene.
 2. The polymer of claim 1 where at least about 30% of themonomer units bear a solubilizing side group.
 3. The polymer of claim 1where R₁ is: ##STR13## and wherein X is selected from the groupconsisting of hydrogen, amino, methylamino, dimethylamino, benzoyl,hydroxy, methoxy, phenoxy, --SC₆ H₅, and --OCOCH₃.
 4. The polymer ofclaim 1 where R₁ is: ##STR14## and wherein X is selected from the groupconsisting of methyl, ethyl, phenyl, benzyl, F, and CF₃, and n is 1, 2,3, 4, or
 5. 5. The polymer of claim 1 wherein R₁ is --CR₅ R₆ Ar where Aris aryl, and R₅ and R₆ are independently selected from the groupconsisting of H, methyl, F, C1 to C20 alkoxy, and OH or R₅ and R₆ takentogether as bridging groups are selected from the group consisting of--OCH₂ CH₂ O--, --OCH₂ CH(CH₂ OH)O--, OC₆ H₄ O--, --OC₆ H₁₀ O-- and--OCH₂ CHR₃ O-- where R₃ is selected from the group consisting of alkyland aryl.
 6. The polymer of claim 1 wherein R₁ is --(CO)X and X isselected from the group consisting of 2-pyridyl, 3-pyridyl, 4-pyridyl,--CH₂ C₆ H₅, --CH₂ CH₂ C₆ H₅, 1-naphthyl and 2-naphthyl.
 7. The polymerof claim 1 wherein R₁ is --SO₂ X and X is selected from the groupconsisting of phenyl, tolyl, 1-naphthyl, 2-naphthyl, methoxyphenyl, andphenoxyphenyl.
 8. The polymer of claim 1 wherein R₁ is --NR₅ R₆ andwherein R₅ and R₆ are independently selected from the group consistingof hydrogen, methyl, ethyl, phenyl, and --COCH₃ or R₅ and R₆ takentogether as bridging groups are selected from the group consisting of--CH₂ CH₂ OCH₂ CH₂ --, --CH₂ CH₂ CH₂ CH₂ CH₂ -- and --CH₂ CH₂ CH₂ CH₂--.
 9. The polymer of claim 1 wherein R₁ is --N═CR₅ R₆ and wherein R₅and R₆ are independently selected from the group consisting of --H,--CH₃, --CH₂ CH₃, phenyl, tolyl, methoxyphenyl, benzyl, aryl, and C1 toC22 alkyl, or R₅ and R₆ taken together as bridging groups are selectedfrom the group consisting of --CH₂ CH₂ OCH₂ CH₂ --, --CH₂ CH₂ CH₂ CH₂CH₂ -- and --CH₂ CH₂ CH₂ CH₂ --.
 10. A free-standing film comprising apolymer of claim
 1. 11. A fiber comprising a polymer of claim
 1. 12. Amolded article comprising a polymer of claim
 1. 13. A coatingcomposition comprising a polymer of claim
 1. 14. The polymer of claim 1where the intrinsic viscosity of said polymer is greater than about 3.5deciliters/gram when measured at 40° C. in a solvent selected from thegroup consisting of 0.05M lithium bromide in N-methylpyrrolidinone,N-methylpyrrolidinone, dimethylacetamide, phenylether, m-cresol,sulfuric acid, anisole, 5% N-methylpyrrolidinone/95% CHCl₃, andchlorobenzene.
 15. The polymer of claim 1 where the intrinsic viscosityof said polymer is greater than about 5 deciliters/gram when measured at40° C. in a solvent selected from the group consisting of 0.05M lithiumbromide in N-methylpyrrolidinone, N-methylpyrrolidinone,dimethylacetamide, phenylether, m-cresol, sulfuric acid, anisole, 5%N-methylpyrrolidinone/95% CHCl₃, and chlorobenzene.
 16. The polymer ofclaim 1 where the intrinsic viscosity of said polymer is greater thanabout 7.2 deciliters/gram when measured at 40° C. in a solvent selectedfrom the group consisting of 0.05M lithium bromide inN-methylpyrrolidinone, N-methylpyrrolidinone, dimethylacetamide,phenylether, m-cresol, sulfuric acid, anisole, 5%N-methylpyrrolidinone/95% CHCl₃, and chlorobenzene.
 17. The polymer ofclaim 1 where the weight average molecular weight of said polymer asmeasured by gel permeation chromatography against polystyrene standardsis greater than about 218,000.
 18. The polymer of claim 1 where theweight average molecular weight of said polymer as measured by gelpermeation chromatography against polystyrene standards is greater thanabout 500,000.
 19. The polymer of claim 1 wherein the tensile modulus ofunoriented 25 micron film of said polymer is greater than about onemillion pounds per square inch.
 20. A soluble rigid-rod copolymer havingrepeat units of the formula: ##STR15## wherein R₁ is independentlyselected from H or a solubilizing side group having molecular weight offrom about 15 to about 300, wherein the intrinsic viscosity of saidcopolymer is greater than about 3 dl/g when measured at 40° C. in asolvent selected from the group consisting of 0.05M lithium bromide inN-methylpyrrolidinone, N-methylpyrrolidinone, dimethylacetamide,phenylether, m-cresol, sulfuric acid, anisole, 5%N-methylpyrrolidinone/95% CHCl₃, and chlorobenzene, wherein at leastabout 30% of the monomer units bear a solubilizing side group, andwherein a portion of the monomer units are absent a solubilizing sidegroup.